US3825317A

US3825317A - Application of a novel photosensitive member to hologram

Info

Publication number: US3825317A
Application number: US00275736A
Authority: US
Inventors: E Inoue; J Tsujiunchi; H Kokado; Y Tokunaga; H Sakuma; H Hanada; T Yamaguchi; I Shimizu
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 1971-07-28
Filing date: 1972-07-27
Publication date: 1974-07-23
Anticipated expiration: 1991-07-23

Abstract

A hologram comprises an interference pattern composed of a mutual diffusion portion of a photoconductor and a metal formed at an exposed portion of a photosensitive member, the photosensitive member containing two constituting elements, that is, a photosensitive receptor containing a photoconductor and a photosensitive intensifier capable of diffusing into the photoconductor when irradiated and at least one of the constituting elements being in a layer form, and the combination of the constituting elements being selected from the group consisting of (i) each of the two constituting elements being in a form of layer, (ii) one constituting element being in a form of layer and the other constituting element being dispersed in said layer, and (iii) one constituting element being in a form of layer and the other constituting element being contacted with the surface of said layer.

Description

w amtucu swat 51 July 23, 1974 SUBSTITUTE FOR MISSING OR 1 APPLlCATlON OF A NOVEL PHOTOSENSITIVE MEMBER TO HOLOGRAM {75] lnventors: Eiichi lnoue; Junpei Tsujiuchi;

Hiroshi Kokado, all of Tokyo; Takashi Yamaguchi, Yokohama; lsamu Shimizu; Hiraku Sakuma, both of Tokyo; Hiroshi Hanada, Yokohama; Yultio Tokunaga, Tokyo, all of Japan [73] Assignee: Canon Kabushiki Kaisha, Tokyo,

Japan [22] Filed: July 27, 1972 {211 Appl. No.: 275,736

152} US. Cl. 350/35, 96/27 H, 96/1 R,

[51] int. Cl G03c 5/04 [58] Field of Search 96/27, 27 H, l R; 350/35 [56] I References Cited UNITED STATES PATENTS 3,491,343 1/1970 Cook 350/35 3,594,167 7/1971 Laming et a1 96/27 H 3,623,787 11/1971 Straile 350/35 3,637,381 1/1972 l-lallman et a1.... 96/27 R 3,644.014 2/1972 Hirschberg 350/35 3,652,276 2/1972 Bartlett 961/27 R 3,655,256 4/1972 Claytor et a1. 350/35 3,660,087 5/1972 Kaspaul et a1. 96/27 R 3,716,359 2/1973 Sheridon 96/27 H 3,733,258 5/1973 l-lanak et a1. 350/35 [57] ABSTRACT A hologram comprises an interference pattern composed of a mutual diffusion portion of a photoconductor and a metal formed at an exposed portion of a photosensitive member, the photosensitive member containing two constituting elements, that is, a photosensitive receptor containing a photoconductor and a photosensitive intensifier capable of diffusing into the photoconductor when irradiated and at least one of the constituting elements being in a layer form, and the combination of the constituting elements being selected from the group consisting of (i) each of the two constituting elements being in a form of layer, (ii) one constituting element being in a form of layer and the other constituting element being dispersed in said layer, and (iii) one constituting element being in a form of layer and the other constituting element being contacted with the surface of said layer.

17 Claims, 33 Drawing Figures L Pmmmmzamm swam-r sew 1m 5 FMS.

3 FIG. no 2 1 y 1 3 HG. H 1 7 V I2 -.2 t 2 V/IZ I 4 I (/2 FIG. i3

Fi 7 5 6 7 l0 9 (/iQ-tl g H wiim fmmzamm SNEU 2 0F 5 FiG. 23K

FiG. i?

@mmbme aa zs an saw an;

CONTENT OF IODINE H. 29 5 6 M E+Q L IOO' Re CC E 30mm U 20min E O min 2 9 50- m g)- min 02) I l min 2 FE F min I l x WAVE LENGTH (mm APPLICATION OF A NOVEL PHOTOSENSITIVE MEMBER TO HOLOGRAM BACKGROUND OF THE INVENTION sitive material is a dry plate of high resolving power' using a silver salt emulsion. Another photosensitive material is a photoresist, but this is poor in resolving power. sensitivity and diffraction efficiency and therefore, is hardly used in practice unless an appropriate application is not found.

Further photosensitive material are dichromate gelatine and thermoplastics, but are inferior to a silver salt emulsion and a photoresist.

Further conventional materials such as a dielectric having light damage effect, a ferromagnetic material capable of recording Curie point and an anodized silicon, are not practically used at the present time.

The dry plate of silver salt emulsion having high resolving power, only one practical photosensitive member for hologram, is further subjected to a bleaching treatment after development and fixation and may be used as a phase hologram. Hologram may be generally classified into a phase type and an amplitude type. The phase hologram records a pattern information as a difference of optical path length so that the hologram appears as a uniform transparent matter by naked eyes while the amplitude hologram records a pattern information as a difference of optical density. It is theoretically confirmed that diffraction efficiency of amplitude hologram is maximum 7.2 percent. On the contrary, diffraction efficiency ofthe phase hologram can be theoretically 1%070. Therefore, a practically usable hologram is only the phase type. When a silver salt emulsion is used for producing a phase hologram, a bleaching treatment is necessary after developing and fixing treatments, but this bleaching treatment is very complicated.

The bleaching treatment step is a delicate step and is closely related with the developing and fixing steps. When the bleaching treatment is mechanized and is conducted automatically, the finishing is largely fluctuated and there occurs irregular bleaching.

Developing, fixing and bleaching steps are wet steps and the operation is not easy. In addition, shrinkage ofthe emulsion layer is disadvantageously caused.

The shrinkage of emulsion layer results in distortion of a hologram pattern and thereby the recorded information is lost. Even ifthe shrinkage is uniform, it is undesirable for a certain purpose and therefore, use of silver salt treated with bleaching is limited to a great extent. Examples of the undesirable uses are optical measurement and color hologram. In optical. measurement the accuracy is lowered and in color hologram there causes a problem of color shift.

Other disadvantages are:

Lathe mechanical strength of an emulsion layer is not sufficient and the durability is not satisfactory when contact with othermatter is necessary; ii) duplicating many holograms is not easy; iii) an emulsion layer is so thick as thicker than 5 microns and so voluminous that a package of high density is not obtained; iv) a process for producing the photosensitive member is complicated and expensive; v) sensitivity, diffraction eff ciency and resolving power are not sufficient; vi) the bleaching treatment is effected by changing the developed silver to silver iodide, but the silver iodide is not a stable compound and there easily causes aging, particularly, photolysis; and vii) the emulsion layer is not always uniform and noise is formed due to fog by development and S/N ratio is not sufficiently high and not suitablefor optical measurement of high accuracy.

SUMMARY OF THE INVENTION According to the present invention, there is provided a hologram which comprises an interference pattern composed of a mutual difiusion portion of a photoconductor and a metal formed at an exposed portion of a photosensitive member, the photosensitive member containing two constituting elements, that is, a photosensitive receptor containing a photoconductor and a photosensitive intensifier capable of diffusing into the photoconductor when irradiated and at least one of the constituting elements being in a layer form, and the combination of the constituting elements being selected from the group consisting of (i) each of the two constituting elements being in a form of layer, (ii) one constituting element being in a form of layer and the other constituting element being dispersed in said layer, and (iii) one constituting element being in a form of layer and the other constituting element being contacted with the surface of said layer.

An object of the present invention is to provide a hologram free from disadvantages of prior art.

Another object of the present invention is to provide holograms of various types.

A further object of the present invention is to provide a hologram capable of forming many reproduced holograms by using a formed hologram as an original.

BRIEF DESCRIPTION OF THE DRAWING I FIG. 20 is apattem exposure step for forming an interference pattern;

FIG. 21 shows a relief pattern;

FIG. 22 shows a pattern exposure step for forming an interference pattern;

FIG. 23 and FIG. 24 show relief interferograms;

FIG. 25 shows a pattern exposure step for forming an interference pattern;

FIG. 26 shows a relief interferogram;

FIG. 27 is a graph showing a relation between iodine content and shift of absorption end;

FIG. 28 shows a diagrammatically enlarged cross section of a reproduced member having a relief pattern;

FIG. 29 diagrammatically show an optical system for regenerating an image information by using a reproduced hologram;

FlG. 30 shows a relation of irradiation time, transmission factor and wavelength;

HG. 31 shows an optical system for conducting a real time holography;

HG. 32 is a photograph showing an interference pattern; and

FIG. 33 shows an optical system for forming a Fourier transformation hologram.

DESCRIPTION OF THE PREFERRED EMBODIMENT in this invention there may be used a photosensitive member comprising a photosensitive receptor composed of or containing a photoconductor, and a photosensitive intensifier capable of causing a mutual diffusion with the photoconductor by an actinic radiation and thereby forming a difference of optical density, refractive index or reflection rate or combination thereof between the mutual diffusion portion and the nonmutual diffusion portion, and the photosensitive receptor contacting the photosensitive intensifier. The photosensitive member is irradiated with a coherent actinic radiation bearing an image information to form an interference pattern corresponding to the image information. Thie interference pattern is formed by the difference ofoptical density. refractive index, reflection rate or combination thereof between the exposed portion and the unexposed portion. Thus, a hologram is produced.

Application of an actinic radiation to the photosensitive receptor results in a mutual diffusion (or mutual reaction) between the photosensitive receptor and the photosensitive intensifier, The photosensitive intensifier is combined with the photosensitive receptor to sensitize the photosensitive member in various manners. The photosensitive intensifier is unified with the photosensitive receptor to receive a part of actinic radiation energy and directly take part in the fundamental process caused by the exposure. The nutual diffusion portion of the photosensitive member formed by actinic radiation different from the photosensitive receptor and the photosensitive intensifier with respect to physical and chemical properties. The mutual diffusion portion serves to form interference patterns of hologram. The difference of optical density, refractive index and reflection rate between the mutual diffusion portion and the original photosensitive material can be directly utilized as hologram. As stated below, when a relief interfe rogram is produced, it can be used as a hologram regardless the difference of physical properties.

ture such as Pbl may be used in the present invention as far as there is a material capable of mutual diffusion with the metal compound crystal. Chalcogen glass is an amorphous material containing atleast one of elements of sulfur group (S, Se, Te) as a main component. Representative chalcogen glass used in this invention are: a simple substance glass such as glass like Se or S; binary chalcogen glasses such as As-S system, As-Te system, As-Se system, S-Si system, Se-S system, Se-Te system, Sb-Se system, Sb-Te system, Bi-Se system, Bi-S system, Ge-S system, Bi-Te system and the like; ternary chalcogen glasses such as As-S-Te system, As-Se-Te system, Sb-As-S system, As-S-Se system, As-S-Ge system, S-Se-Ge system, As-Se-Ge system and the like; quaternary chalcogen glasses such as As-S-Se-Te system, As-S-Se-Ge system and the like.

Furthermore, other representative chalcogen glasses are a mixture of the above mentioned chalcogen glass systems, and a chalcogen glass to which there is added one or more of halogen, thalium (Tl), copper, silver, cadmium, lead, alkali metal such as Na, K and the like, alkaline earth metal such as Ca, Sr and the like, elements of Nb group of the Periodic Table such as Si, Ge and the like, lanthanum rare earth elements such as Eu, Sm and the like, actinide rare earth elements such as U and the like. The glass like material is a material having glass transition temperature and includes a glass like material containing a crystellite material.

As organic materials having photoelectroconductivity, there may be mentioned vinyl carbazole, poly-9- vinyl carbazole, halogenated poly-l-vinyl carbazole, amino polyphenyl, N ,N ,N ,N -tetrabenzyl-pphenylenediamine, 4-4'-bis-dimethylaminobenzophenone, diphenylmethane dye leuco base, triphenylmethane dye leuco base, polyvinyl anthrathene, poly-2-vinyl dibenzo-thiophene and the like. Photoconductive organic materials are usually used together with sensitizers. As sensitizer, there may be mentioned dye sensitizers and electron attractive compounds.

Examples of dye sensitizer are as follows:

i. dicarbazylmethane or tricarbazylmethane having the formula 1 Rs X" where R, is aryl such as phenyl, halogen-substituted phenyl, nitrophenyl, dialkylaminophenyl, alkoxyphenyl, carbazole residue, substituted carbazole residue and the like; R and R are, similar or dissimilar, hydro gen and/or C -C alkyl; R, and R are, similar or dissimilar, hydrogen, C C, alkyl, C C, alkoxy, halo, nitro, and/or dialkylamino; and X is anion. ii. cyanine dye having the formula CH; CH1 CH1 CH;

i s .1 Ii

where X is one nitro group or 1-2 halogens; R is alkyl of not higher than C A is (CH=CH),.-CH= where n is an integer of -2,

where R is a lower alkyl of C -C and B is anion.

iii. dialkylaminostyryl dye of the formula or -CH=CH in which R is hydrogen or lower alkyl and R is hydrogen or lower alkyl; B and C are, similar or dissimilar, methine, substituted methine and nitro gen, when it is carbon, hydrogen or an alkyl is attached to the B and C in the formula; R, and R are, similar or dissimilar, hydrogen, halogen such as Cl, Br and I, N0 COO? where R is loweralkyl, and R, and R taken together, may form a six membered ring, but when both B and C are carbon, there are excluded R =R H and a six membered ring formed by R and R R is alkyl of not higher than C R and R are, similar or dissimilar, lower alkyl of not higher than C,; X is anion and n is an integer of 1 or 2.

iv. Brilliant Blue, Victoria Blue B, Methyl Violet, Crystal Violet, Rhodamine B, Rhodamine Extra and the like.

As electron attractive compounds, there may be mentioned 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, 2-chloroanthraquinone, halides such as tetrabromomethane, chlorotribromomethane, iodoform, hexabromoethane and the like.

As crystalline material having no glass transition temperature, there may be mentioned oxides, halides, sultides, selenides, arsenides, tellurides and intermetallic compounds of Cu, Zn, Cd, Hg, Ga, In, Tl, Pb, Sn, Sb

and Bi. Examples of such m'a'teriar are'Cul, Phl PbCl CdCl CuCl. Sblg, PbS, CdS, ZnS, PbSe, CdTe. GaAs, lnAs, ZnO, and lnSb.

The photosensitive intensifier is a material capable of mutually reacting with and diffusing into a photosensitive receptor.

Representative photosensitive intensifiers are a metallic solid material, a compound capable of forming a metallic material upon decomposition, liquid material or finely divided material dispersed in a liquid, and gaseous material. Examples of the metallic material are metals such as Ag, Zn, Cd, Mn, Ga, Ni, Cr, Cu, In, Bi, Sn and TI, alloys containing the above mentioned metal or metals, and various materials capable of forming the metal or metal ion upon decomposition. Furthermore, there may be mentioned semiconductors of Si or Ge, intermetallic compound such as Ga-As and In-Sb, halogen element, halogen ion, semi-metal of Group V of Periodic Table such as As, Sb and the like, and chalcogen elements such as S, Se and Te.

Particularly effective photosensitive intensifiers are Ag, Cu or an alloy containing at least one of them. As an alloy, an alloy of low melting point is preferable. There may be mentioned, for example,

AgBi (Bi not less than AgCd (Cd not less than 95%) AgGa (Ga not less than 55%) AgHg (I-Ig -95%) Agln (In not less than 70%) AgLi (Li not less than 9%) AgPb (Pb not less than 93%) AgTe (Te 62-86%) AgTl (Tl not less than 92%) Cu-Ga (Ga not less than 87%) CuHg (Hg not less than Cu-In (In not less than 95%) Cu-Sn (Sn not less than 93%) and Cu-Te (Te 78-86%).

A representative embodiment of the photosensitive member according to the present invention has two constituting elements which are in a form of layer and are laminated each other. This embodiment is shown in FIG. 1 and FIG. 2. FIG. 1 shows a photosensitive member composed of a support 2, a photosensitive receptor layer 1 overlying the support 2 and a photosensitive intensifier layer 3 overlying the photosensitive receptor layer 1. FIG. 2 shows a photosensitive member composed of a support 2, a photosensitive intensifier layer 3 overlying support 2 and a photosensitive receptor layer 3 overlying the photosensitive intensifier 3. Another embodiment of the photosensitive member has one constituting element in a form of layer and the other constituting element is dispersed in the layer of the former constituting element. This embodiment is shown in FIG. 3 and FIG. 4. FIG. 3 shows a photosensi' tive member composed of support 2 and a layer of photosensitive receptor 1 overlying support 2, and in the layer of photosensitive receptor 1 are dispersed particles 3 of a photosensitive intensifier. FIG. 4 shows a photosensitive member being composed of support 2 and a layer of photosensitive intensifier 3 overlying support 2. In the layer of photosensitive intensifier 3 there are dispersed particles of photosensitive receptor 1. A further embodiment of a photosensitive member has one constituting element in a form of layer and the other constituting element which is contacted with the surface of the former constituting element when or immediately after subjected to pattern exposure for producing an interference pattern. This embodiment is shown in FIG. 5 and FIG. 6. FIG. 5 shows a photosensitive member composed of support 2 and a layer of photosensitive receptor 1, wherein, though photosensitive intensifier is not shown, a photosensitive intensifier is contacted with the layer 1 in a form of gas, liquid or a thin layer when or immediately after subjected to pattern exposure for producing an interference pattern. FIG. 6 shows a photosensitive member composed of support 2 and a layer of photosensitive intensifier 3, wherein, though a photosensitive receptor is not shown, the photosensitive receptor is contacted with the layer 3 in a form of gas, liquid and a thin layer when or immediately after subjected to pattern exposure for producing an interference pattern. In reference to photosensitive members as shown in FIG. l-FIG. 6, thickness of each layer of a photosensitive receptor and a photosensitive intensifier usually ranges from 1 mm to ID m t, preferably, from 30 t to 10 mpt, but the thickness may be thicker than said range. And further, in reference to photosensitive members as show in FIG. 1 FIG. 6, photosensitive members with no support may be used for producing an interference pattern. In this embodiment, the thickness of layer of a photosensitive receptor or photosensitive intensifier is usually not less than 10 t which gives self-supporting strength to the layer. Particularly, in the photosensitive members as shown in FIG. 1 and FIG. 2, the thickness ofa layer of photosensitive receptor preferably ranges from 3 to 30 my. and that of photosensitive intensifier preferably ranges from 0.2 )IL to l0 mu from viewpoint of resolving power. A support used in this invention may be glass, ceramics, cyrstal, metal, semiconductor, resin, organic film, paper, cloths and composite materials. Each layer of a photosensitive receptor and photosensitive intensifier may be produced by conventional art such as vapor depositing under vacuum, sputtering, melt coating and the like, and, in case that the layer is thick, it may be also produced by cutting off, polishing and the like. A layer of photosensitive receptor containing dispersed particles of a photosensitive intensifier as shown in FIG. 3 may be produced by such a method that a photosensitive receptor containing particles of a photosensitive intensifier is melted to form a layer on the support and that a thin film or particles ofa photosensitive receptor is applied to particles placed uniformly on the support followed by heating to melt the photosensitive receptor.

In the layer of a photosensitive receptor containing dispersed particles of a photosensitive intensifier, the photosensitive intensifier may be usually contained in a ratio from 0.01 to 5 parts by weight per I00 parts by weight ofthe photosensitive receptor.

A layer of a photosensitive intensifier containing particles of a photosensitive receptor as shown in FIG. 4 may be produced by such method that a photosensitive intensifier containing particles ofa photosensitive recptor is melted on the support to form a layer and that a thin film or particles of a photosensitive intensifier is applied to particles of photosensitive receptor placed uniformlyon the support followed by heating to melt the photosensitive intensifier. In the layer of photosensitive intensifier containing particles of a photosensitive receptor, the photosensitive intensifier is preferably present in a ratio of l parts by weight based on 100 8 parts by weight of the photosensitive receptor. It is preferred to use a metal of low melting point as a photosensitive intensifier for producing the layer containing the particles of a photosensitive receptors. The following table gives representative metals having low melting point.

Table Alloy Composition by weight) (C) Bi(44.7)Pb(22.6)Sn(8.3)Cd(5.3)ln(l9.l) 46.7 'Bi(35.6)Pb(49.l)Hg(l5.3) I06 Bi(50.0)Pb(26.7)Sn(l3.3)Cd(l0.0) In (40) Ga (60) 60 Bi (48.0) Pb (28.5) Sn (l4.5) Sb (9.0) 227 Bi (56.0) Sn (40.0) Zn (4.0) I Bi(53.59)Pb(42.4l)Sb(4.0) I58 Sn (73.5) Cd (24.5) Zn (20) I63 Sn (7L0) Zn (9.0) I99 Sn (98.0) Mn (2.0) 200 Sn (96.5) Ag (3.5) ZZI Pb (87.5) Sb (12.5) 247 Particles of a photosensitive receptor and a photosensitive intensifier may be produced by methods such as atomization of melted material, crushing by means of a vibrating mill, balling mill, mortar and the like, and chemical precipitation. Referring to the photosensitive member as shown in FIG. 5, the liquid photosensitive intensifier may be applied in a state of melted form under heating. In this case, it is preferred to use metal alloy having low melting point as described in the aforesaid table, and the gaseous photosensitive intensifier may be applied to the photosensitive receptor layer by vapor depositing under vacuum simultaneously with pattern exposure.

Referring to the photosensitive member as shown in FIG. 6, the liquid and gaseous photosensitive receptor may be applied in a similar manner to that of the liquid and gaseous photosensitive intensifier described above in FIG. 5.

The photosensitive members shown in FIG. 1 -FIG. 6 are typical embodiments of photosensitive member used for producing an interference patter. According to the present invention, photosensitive members other than these of FIG. I FIG. 6 may be used in the present invention. For example, they are a photosensitive member composed of a layer of phtosensitive receptor, a layer of photosensitive intensifier and a layer of phtosensitive receptor, which is formed by overlaying a layer of photosensitive receptor on the layer of photosensitive intensifier 3 shown in FIG. 1, and a photosensitive member composed of photosensitive receptor layer-photosensitive intensifier layer-photosensitive receptor layer-photosensitive intensifier layer produced by providing further a photosensitive receptor and a photosensitive intensifier on the photosensitive intensifier layer 3 of FIG. I. Further, these may be used a photosensitive member composed of photosensitive intensifier layer-photosensitive receptor layerphotosensitive intensifier layer as produced by laminating a photosensitive intensifier layer on the photosensitive receptor layer l in FIG. 2 and a photosensitive member composed of photosensitive intensifier layerphotosensitive receptor layer-photosensitive intensifier layer-photosensitive receptor as produced by laminating a phtosensitive intensifier layer and then a photosensitive receptor layer on the photosensitive receptor layer 1 in FIG. 2.

In general, the photosensitive members as shown in FIG. 1 and FIG. 2 may be used by further overlaying alternately a photosensitive receptor and a photosensitive intensifier though a treatment step in the formation of relief interferogram for such photosensitive member is complicated.

in FIG. 3, a photosensitive receptor layer and/or a photosensitive intensifier may be provided on the photosensitive receptor layer 1 containing dispersed particles of the photosensitive intensifier 3 or between the photosensitive receptor layer 1 and the support 2.

In FIG. 4, in a way similar to FIG. 3 above, there may be provider a photosensitive receptor layer and/or a photosensitive intensifier layer on the photosensitive intensifier layer 1 or between the photosensitive intensifier layer I and the support 2.

As mentioned above, according to the present invention there may be used a photosensitive members of FIG. 1 FIG. 6 having additionally one or more constituting elements. From commercial point of view, a simple structure of photosensitive member is generally preferred.

Representative methods of producing holograms according to the present invention are as shown below.

Referring to FIG. 7, the optical system for forming hologram includes a laser 5, an inverted telescope 6 for enlarging the laser flux, a beam splitter 7, an information source 8 to be recorded, a photosensitive member 9, a reference beam 10 and a light from body 11. The interference fringe of the reference beam 10 and the light from body 11 is recorded as hologram. Regeneration is conducted by intercepting the light 11 and illuminating only the reference beam 10 to regenerate the wave front of light 11.

The present invention can be, in principle, effected by an exposing treatment only, but a further effective hologram may be obtained by carrying out an additional treatment since application of hologram is practical and wide.

Hologram may be produced by applying a coherent actinic radiation having an image information to a photosensitive member to form on the photosensitive member an interference pattern corresponding to the image information produced by a difference of optical density, refractive index, reflection rate, or combination thereof caused by mutual diffusion phenomena, and then chemically or mechanically removing the remaining photosensitive receptor or photosensitive intensifier or both of them not taking part in the mutual diffusion. A relief interferogram may be produced by forming an interference pattern on a photosensitive member, and mechanically and chemically removing selectively a photosensitive receptor or intensifier at an ilfi exposed or unexposed por fionfor both of them to form a relief interferogram as hologram.

Further, the relief interferogram thus obtained may be used as an original hologram and a transferring material be closely contacted with the original pattern to reproduce the hologram.

The relief pattern may be produced by removing partly in the direction of thickness of the constituting element layer as well as removing wholly.

The interference patterns is usually formed in the photosensitive receptor, and the mutual diffusion phenomemon, a photosensitive response of photosensitive member, starts at the interface between the photosensitive receptor and the photosensitive intensifier, and then the diffusion occurs both in the photosensitive receptor and the photosensitive intensifier depending upon the intensity of actinic radiation and the diffusion portion is formed in both of them. The interference pattern is thus formed in both of them, and the interference pattern formed in the photosensitive intensifier may be used as hologram. in this case, it is necessary that the photosensitive intensifier is a solid layer and highly transparent. In addition, it is necessary to select and use a member of high mechanical strength.

The interference pattern formed on a photosensitive intensifier may be changed to a relief pattern by removing the exposed portion or unexposed portion. Techniques and apparatuses used for recording a hologram on a photosensitive receptor may be applied to recording a hologram on a photosensitive intensifier.

Production of hologram by using photosensitive members in FIG. 1 FIG. 6 is explained below.

FIG. 8 FIG. 13 shows a process for producing a hologram by using an apparatus in FIG. 7, but the information source 8 in FIG. 7 is replaced by an original pattern P in FIG. 9 having a light portion B and a dark portion A. FIG. 8 shows a starting member. FIG. 9 shows a state in which the member is exposed to a hologram pattern, anda mutual diffusion between the photosensitive intensifier and the photosensitive receptor at the exposed portion and the photosensitive intensifier diffuses to form a mutual diffusion portion 12. In FIG. It), the unexposed photosensitive intensifier is removed from the member. in FIG. 11, the photosensitive receptor at the unexposed portion is removed. In FIG. 12, a surface of the support exposed by completely removing the constituting elements at the unexposed portion is subjected to an etching treatment. In FIG. 13, the mutual diffusion portion 12 in FIG. 12 is removed. Further, when the photosensitive intensifier is thick or the amount of actinic radiation is little as compared with thickness of the photosensitive intensifier, the mutual diffusion portion is not formed over the whole length of the photosensitive receptor layer and the photosensitive intensifier layer in the vertical direction, but there remains a photosensitive intensifier not participating in the formation of the mutual diffusion at a portion near the surface of the exposed portion. In this case, the photosensitive intensifier remaining at the exposed portion is removed when the photosensitive intensifier at the unexposed portion is removed for obtaining the state as shown in FIG. It). Removing the remaining of photosensitive intensifier is actually effected simultaneously with removing of the photosensitive intensifier at the unexposed portion.

The patterns shown in FIG. 9 FIG. 13 form interference patterns and can be used as holograms. When the pattern shown in FIG. 9 is used as hologram. there is used a photosensitive member having a thin and substantially transparent photosensitive intensifier layer and having a low sensitivity, and a strong hologram pattern exposure is applied to the photosensitive member to form an interference pattern, and a weak light is used for regeneration.

The patterns shown in FIG. 10 FIG. 13 give a hologram having a larger phase contrast and give a fixed holograni.

The pattern in FIG. 10 is formed usually by treating the photosensitive member with an acid solution. A metal photosensitive intensifier can be dissolved and removed by an acid. An amphoterie metal such as zinc can be removed by an alkali. On the contrary, the mutual diffusion portion is not dissolved by a usual acid treatment. The pattern in FIG. 11 may be formed by removing the photosensitive receptor in FIG. 10 with the agent capable of dissolving the photosensitive receptor. When the photosensitive receptor is a chalcogen glass, an alkali solution is usually used for dissolving and removing. When the photosensitive receptor is an organic photoconductor, an organic solvent is usually employed for dissolving and removing. Further when the photosensitive receptor is a photoconductor of metal compound, an acid solution is used for dissolving and removing.

A mutual diffusion portion is not dissolved in a usual acid, alkali or organic solvent. The pattern in FIG. 12 is formed by treating the member in FIG. 11 with an agent capable of dissolving the support. For example, when the support is a metal, an acid or alkali is used and when the support is a glass, hydrogen fluoride is used. and further when the support is resin, an organic solvent is used.

The pattern in FIG. 11) FIG. 13 correspond to a positive pattern with respect to the original pattern by removing the unexposed portion in FIG. 9. On the contrary, it is also possible to form a negative pattern by removing the mutual diffusion portion taking advantage of the poor mechanical strength ofthe mutual diffusion portion. The negative pattern is such a pattern that the photosensitive receptor 1 and the photosensitive intensifier 3 are exchange each other in FIG. 14 FIG. 18. The removing of the mutual diffusion portion for the purpose of forming such negative pattern is effected by placing the member as shown in FIG. 9 in water or an organic solvent such as alcohols, toluene and the like and applying a mechanical vibration to the solvent or the member, or by adhering an adhesive tape to the whole surface of the member and then peeling the tape to remove the mutual diffusion portion.

The method of producing the negative pattern by peeling off the mutual diffusion portion is conducted by using a. mechanical means and therefore, the resolving power of the resulting negative pattern is lower than the positive pattern as shown in FIG. 10 FIG. 13.

FIG. Id FIG. 18 show a process for producing hologram by using the photosensitive member of FIG. 2. A photosensitive intensifier layer is provided on a support and then a photosensitive receptor layer is provided on the photosensitive intensifier layer to form the photosensitive member. The mechanical strength of the mutual diffusion portion formed in such a photosensitive member is lower then that of the mutual diffusion portion in FIG. It) and FIG. 8, and particularly, the adhesion strength with the support is remarkably low. Tak- I2 ing advantage of the above fact, the mutual diffusion portion formed in FIG. 14 may be removed by the same removing procedure of mutual diffusion portion as in FIG. 9. Particularly, the removing of the mutual diffusion portion formed in FIG. 14 may be effected with a diluted alkali solution or acid solution. In this case, the diluted alkali or acid penetrate the interface between the mutual diffusion portion and the photosensitive receptor, the photosensitive intensifier and the support, and thereby the mutual diffusion portion is cut off from the photosensitive member. When the photosensitive receptor is a chalcogen glass, a diluted alkali not only removes the mutual diffusion portion, but also dissolve the photosensitive receptor. However, the removing of the mutual diffusion portion proceeds faster than that of the photosensitive receptor. In this way, the pattern as shown in FIG. 15 is formed. Further, when the photosensitive receptor layer is too thick as compared with the amount of radiation in FIG. 14, all of the photosensitive receptor and the photosensitive intensifier do not always form a mutual diffusion portion, but a part of photosensitive receptor and photosensitive intensifier remains without forming mutual diffusion portion. In this case, the mutual diffusion portion is removed after removing the photosensitive receptor remaining at the exposed portion. For example, it may be removed simultaneously with removing the mutual diffusion portion with a diluted alkali solution. The pattern in FIG. 15 may be converted to other pattern. In FIG. 16 the photosensitive receptor is removed and the member in FIG. 17 is formed by etching the exposed support in FIG. 15. In FIG. 18, the exposed support surface of the member in FIG. 16 is etched. The member in FIG. 19 is formed by removing a photosensitive intensifier 3 in FIG. 18.

Removing of photosensitive receptor, removing of photosensitive intensifier and etching of support are effected by the such methods as used in formation of FIG. 10 FIG. 13. Each of FIG. 14 FIG. 19 may be used as hologram. FIG. 16, FIG. 18 and FIG. 19 may be used as a fixed hologram. The patterns shown in FIG. 15 and FIG. 17 may be used as hologram by applying a blanket irradiation to convert the projected portion of the pattern to mutual diffusion portion.

FIG. 20 and FIG. 21 show a pattern forming process using a photosensitive member shown in FIG. 3. The pattern in FIG. 21 is formed by removing the unexposed portion of the member in FIG. 19. Removing of the unexposed portion is conducted by using an agent capable of dissolving the photosensitive receptor. In this case, the photosensitive intensifier 3 dispersed therein is also simultaneously removed. Removing of the photosensitive receptor 1 may be carried out by the same method as used in the formation of pattern in FIG. II. The pattern in FIG. 21 may be converted to patterns as shown in FIG. 12 and FIG. 13. The patterns in FIG. 20 and FIG. 21 may be used as hologram. The pattern in FIG. 21 gives a fixed hologram.

The formation of hologram by using the photosensitive member in FIG. I may be conducted in a way similar to that in FIG. 20 and FIG. 21. Since the mutual diffusion portion formed in the photosensitive member shown in FIG. 4 is particularly poor in point of mechanical strength, the mutual diffusion portion may be removed by a method as used for the formation of pattern in FIG. 15 to produce a positive pattern as shown in FIG. 6 with respect to the original pattern.

2 l i l The pattern formed by using a photosensitive memher in FIG. 4 may correspond to that of FIG. 20, FIG. 21 and FIG. 16 and each may be used as hologram. When the support of these patterns are etched as shown in FIG. I2, FIG. 13, FIG. 18 and FIG. 19, they may give hologram of other pattern.

FIG. 22 -FIG. 24 show a representative process for forming a pattern using a photosensitive member in FIG. 5. In FIG. 22, a gaseous photosensitive intensifier 3 is contacted with the surface of the photosensitive receptor I ofthe photosensitive member in FIG. and an actinic radiation is applied through an original pattern to the photosensitive member to form a mutual diffusion portion caused by diffusion of the photosensitive intensifier into the photosensitive receptor at the exposed portion and form a photosensitive intensifier layer 3 at the unexposed portion since the photosensitive intensifier does not diffuse, but deposits. The pattern thus formed gives a fixed pattern by removing the photosensitive intensifier layer 3 at the unexposed portion (FIG. 23). By subsequently removing the photosensitive receptor. there is formed a pattern in FIG. 24. Removing of the photosensitive receptor and the photosensitive intensifier may be effected by the same method as that used in the pattern formation process in FIG. and FIG. II. The patterns in FIG. 22 FIG. 24 may be used as hologram. The members in FIG. 23 and FIG. 24 maybe utilized as fixed holograms. The pattern in FIG. 24 may be converted to the pattern as shown in FIG. 12 and FIG. 13. The pattern in FIG. 22 may be converted to a series of pattern as shown in FIG. 16, FIG. 18 and FIG. 19 byapplying a method for forming the pattern in FIG. and removing the mutual diffusion portion to form positive patterns.

FIG. 25 and FIG. 26 show a representative process for forming a pattern using a photosensitive member in FIG. 6. In FIG. 25, a gaseous photosensitive receptor 1 is contacted with a photosensitive intensifier layer 3 of the photosensitive member in FIG. 6 and a pattern actinic radiation is applied thereto to form a mutual diffusion portion by diffusing the photosensitive receptor into the photosensitive intensifier at the exposed portion and form a photosensitive receptor layer 1 at the unexposed portion by depositing of the gaseous photosensitive receptor. The mutual diffusion portion thus formed has poor mechanical strength, and a pattern shown in FIG. 26 is obtained by applying the same pattern forming method as used in formation of FIG. 15. The patterns in FIG. 25 and FIG. 26 are used as hologram. The pattern in FIG. 26 may be converted to a pattern where a projected portion of the pattern is changed to a mutual diffusion portion, and the resulting pattern may be used as hologram. The pattern in FIG. 26 may be converted to patterns as shown in FIG. I6, FIG. 18 and FIG. 19. In FIG. 9, FIG. 14, FIG. 22 and FIG. 25, the pattern exposure may be effected from the support side if desired. In the foregoing, the formation of hologram is explained, but the above formation methods are a part of many possible methods and the present invention is not limited by them.

As acid or alkali solution for forming patterns in the present invention, there may be used usual acid and alkali. Representative examples are acids such as hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and the like, chromic (K CrgOfi H 504), ammonium nitrate, ammonium persulfate, ferric chloride, ferric nitrate, red prusacid mixture siatepotassium bromide mixture? Representative alkalis like.

The formed pattern may be further treated if desired. For example, when the support is electroconductive and the photosensitive intensifier is metal, the member may be plated to convert the member to a plating pattern and produce a relief plating layer on the support. The formation of such plating layer is based on a phenomenon that the metal diffuses into the chalcogen glass to form a diffusion portion of a resistance as low as about 10 ohm.cm. and the plating is selectively-conducted on the diffusion portion while the high resistance layer at the unexposed portion is gradually dissolved in the plating liquid and lost.

With respect to a fixing treatment, when in the pattern as formed in FIG. 9 and FIG. 22 the photosensitive intensifier is a metal such as silver and copper or an alloy such as alloy of copper and silver, this metal or alloy is changed to the iodide or bromide to form a transparent and in active one. An example of the chemical reaction is as follows:

2Ag +I 2Agl When the photosensitive intensifier is a metal layer,

the metal layer may be removed by amalgamation with mercury. When the photosensitive receptor is a chalcogen glass and the chalcogen glass contains halogen, there is obtained a pattern in which the change of light transmission at the exposed portion is substantially negligible small, and such a pattern is particularly preferable as phase hologram. In other words, the pattern at the mutual diffusion portion is observed as a pattern of transmission factor. A portion where a photosensitive intensifier is diffuse into a chalcogen glass by a radiation energy has a decreased transmission factor. Measurement of the spectral transmission factor shows that the absorption end when the photosensitive intensifier is diffused shifts to a long wavelength side. Such pattern is formed by change of optical density or decrease or increase of reflection light due to difference of absorption. The information is recorded by so-called formation of visible image. Thus, when this is used as hologram, it is an amplitude hologram and not desirable.

On the contrary, it has now been formed that when a halogen is preliminarily added to a chalcogen glass, the absorption end is not shifted even if a photosensitive intensifier is diffused by actinic radiation and therefore, the transmission factor is not substantially changed. but the refractive index is changed and thereby, a phase hologram is obtained. It is considrered that a substantial bleaching is effected by the reaction of metal and the halogen. In addition, when a halogen is added, the sensitivity of photosensitive member is advantageously increased.

As the halogen, there may be preferably used iodine and bromine. but chlorine and fluorine also can be used. In the following, the present invention is explained referring to iodine as an example.

The amount ofiodine to be added is restricted mainly by experience. In other words, when the amount of iodine is extremely large, the melting point or glass transition point is markedly lowered and thereby there disadvantageously occurs softening or crystallization at room temperature, or the mechanical strength is lowered. The maximum amount of iodine depends upon the composition of the chalcogen glass. It is desirable to limit the iodine amount to such a valve that the glass trasition temperature is higher than 50 deg. C. The content of iodine corresponding to the above limitation is less than 80 percent by weight, preferably less than 60 percent. When the amount of iodine is less than 0.01 percent. the shift at the absorption end becomes large and this not desirable Particularly preferable amount of iodine is higher than 0.1 percent. When iodine is added to A5253. a representative chalcogen glass, which contains about one atom of Ag per 1,000 atoms constituting the chalcogen glass. the relation of the absorption end shift (AA) and the iodine content is shown in FIG. 27 and a table below. Content of iodine shown in the following table and in this specification is represented by the following percentage.

Weight of added iodine x 100 (76) Total weight of chalcogen glass containing the added iodine As is clear from FIG. 27 where the values in the above table are plotted, addition of only a small amount of iodine causes a large change of A)\.

In the foregoing, there is described that addition of halogen to chalcogen glass is very effective. This desirable effect by halogen is also recognized the photosensitive member as shown in FIG. I FIG. 6.

FIG. 23 shows a member 14 having a relief pattern reproduced from relief patterns as shown in FIG. 6 FIG. 26.

FIG. 29 shows an optical system for regenerating an image information from the reproduced hologram as shown in FIG. 28. A light flux emitted from laser 5 is enlarged by an inverted telescope 6 and illuminates a member having a reproduced relief pattern 14 as a reference beam. A primary diffraction light 15, i.e., a light having a regenerated wave front, shows good diffraction efficiency since the member I4 is are excellent phase hologram. Recording and regenerating of hologram may be simultaneously conducted. In other words, it is possible that a light to which a photosensitive member is sensitive, i.e. a coherent light having a wavelength corresponding to spectral sensitivity range of the photosensitive member, is projected to record hologramsimultaneously with regenerating hologram by using a light of a wavelength outside of the spectral sensitivity range as reference beam. In this case, the coherent light is preferably argon light (4,880 A) and the reference beam is preferably lie-Ne light (6,328 A).

Further, a hologram having a relief interferogram has an effect to make a phase contrast into a non-linear Contrast with respect to the radiation intensity, and higher order diffraction light can be regenerated in high efficiency. Furthermore, upon regeneration, the distance substantially corresponding to interference fringe distance in a regenerated interference pattern 36 can be reduced to a grea'texteht to enable a highly accurate measurement.

Accordingly, as a further embodiment of forming a hologram according to the present invention, it is very effective to use a hologram having an interference pattern formed by using various photosensitive plate as an original pattern and projecting the original pattern to a photosensitive plate used in this invention to reproduce the interference pattern. In this case, the original pattern is already an interference pattern as hologram and therefore, it is not necessary that the irradiation light for the original pattern is a coherent light, but a visible light and an ultraviolet light may be satisfactorily used. The original pattern may be naturally a pattern formed at the exposed portion as shown in FIG. 1 FIG. 6. It is particularly effective in case that an interference pattern formed on a silver salt photographic dry plate is used as an original pattern to form a reproduction of interference pattern on a photosensitive member used in this invention.

For example, in FIG. 9, FIG. 14, FIG. 20, FIG. 22 and FIG. 25, when the original pattern P is an interference pattern of hologram formed on a silver salt photographic dry plate (light and shade interference pattern before bleaching treatment), the original interference pattern is reproduced on the photosensitive member by pattern exposure with an ordinary light. The reproduced pattern may be changed to various relief pattern as explained in FIG. 9 FIG. 26.

As described above, it is very advantageous to reproduce on a photosensitive member an already formed interference pattern usable as hologram since i) the pattern thus reproduced has a phase amplifying effect, ii) the pattern thus reproduced has a physical strength higher than and a durability better than the bleaching pattern of silver salt, iii) a relief pattern can be reproduced by press-transferring an original relief pattern to a resin film, iv) a light and shade interference pattern formed on a highly sensitive silver salt photographic dry plate can be reproduced on a photosensitive member suitable for hologram without bleaching.

By using a photosensitive member having a wide dynamic range with respect to spectral photosensitive characteristic, there may be recorded and regenerated a Fourier transformation hologram and thereby, high density hologram can be recorded and regenerated.

In summary, the advantages of the present invention are as shown below.

The sensitivity of the photosensitive member may be enhanced, if desired, and there can be obtained a sensitivity as high as or higher than that of a silver salt dry plate of high resolving power, and therefore, the exposure time may be shortended and an adverse effect or vibration can be avoided. This fact enables to use a practical hologram production apparatus without employing a large bed of the upparatus for avoiding vibration.

Further, the treating time until development is so short that the regeneration of real time holography is possible. This point is particularly important in case of using holography for precise measurement. Heretofore, the time from production of hologram to regeneration takes at least about one hour including developing, fixing, washing with water, bleaching, washing with water, and further a particular room for the treatment is necessary. In the present invention, the development is effected only by light projection and thereby the real time holography is possible. The treatments such as fixing and etching necessitates only several tens seconds at most and the diffraction efficiency is enhanced by' the fixed state or etching and the non-linear photosensitivc characteristics are emphasized to enable substantially a real time regeneration. These treatments are so simple that any particular room is not necessary. The whole process can be made into a precision measurement apparatus.

In addition, there is no shrinkage of photosensitive layer of the photosensitive member and therefore, precise optical measurement of color holography and precise regeneration of fine images can be effected.

Furthermore, it is possible to directly transfer the relief pattern produced by etching on the hologram member of the present invention onto plastics and thereby may reproduced holograms can be produced efficiently and at low cost. Therefore. the present invention capable ofdirectly forming a reproduced master is far better than prior art reproduction, for example, which comprises forming hologram on a silver salt dry plate, printing the hologram on a photoresist, replacing by a relief pattern of photoresist and then reinforcing the surface of the resist material with a metal film to form a reproduced master.

In addition, since the photosensitive member according to the present invention has a wide dynamic range, that is, a range in which the reciprocity law is applicable, it is suitable for producing a hologram of light from a body having high contrast and further suitable for Fourier transformation hologram capble of concentrating a light from body to a small area, and therefore, it is possible to record at high density and the hologram of the present invention is effectively used for information treatment as a high density fixing memory element.

The following examples are given for illustrating the present invention, but by no means for restricting the present invention.

EXAMPLE 1 A layer of chalcogen glass of A 5 I containing percent of iodine was coated by (vapor-depositing) in thickness of about 500 millimicrons on a white glass plate 1 mm. thick) and then Ag was coated by vapordepositing in thickness of millimicrons on the above layer of the chalcogen glass. The members thus obtained was illuminated strongly from the Ag layer side by a super high pressure mercury lamp of 250 W. set at 25 cm. from the said member. When all surfaces of the member were illuminated, a mutual action occurred between the chalcogen glass and AG and the Ag layer diffused into the chalcogen glass and the metallic color disappeared. A percent transmission of the memoer increased as the illumination time increased, and it spectrally shown in FIG. 30. In FIG. 30, the spectral transmittance at each stage of illumination time is shown, in which it is clear that the layer of Ag nearly completely disappeared by illumination for 30 min. and the spectral transmittance at the above case is almost consistent with the spectral transmittance Re in the case that .Ag is not diffused. Even if the illumination time is short, ifthe layer of Ag is removed, the spectral transmittance is almost consistent with that in the case that Ag is not diffused.

When the member is used for a phase hologram, the metal layer remaining on the surface should be re- 1g moved. Removing the metal layer on the surface is necessary to prevent gradual exposure of a highly sensitive photosensitive material under natural light.

An oxidation bath, particularly acid or oxidation bath, is suitable for removing a metal layer. The representative examples are a mixture of sulfuric acid and chromic acid, mitric acid, ammonium nitrate solution, ferric nitrate, ammonium persulfate and the like.

EXAMPLE 2 A layer of chalcogen glass of As Se Te I containing 20 percent of iodine was coated by flash evaporation in thickness of about 300 millimicrons on a glass plate, and furthermore the semitransparent layer of Ag was formed in thickness of 50 millimicrons over the above layer. A fourier transformation hologram was made by illuminating the above member set at the focal surface of a lens having mm. of focal length by an argon ion laser of mW. In the above case, the illuminated area of the surface of the member was about 1 cm and exposure was completed by exposing for about 1/10 second. Thereafter, the remaining Ag layer was removed and a hologram was regenerated, and it was found that the image could be regenerated at a high diffraction effeciency of about 40 percent.

EXAMPLE 3 A melted body of chalcogen glass composed of As S and Br containing 30 weight percent of Br was obtained by adding AsBr and S to As S and melting in an atmosphere of argon at 550C, 1 atomospheric pressure for 3 hours. The melted body was coated on a base plate in thickness of about 5 microns by a spinner. Temperature of the melted body was about 100C when coated, but the melted body was sufficiently fluid. The plate thus coated became a photosensitive member by cooling rapidly an thereafter by vapor-depositing a thin film of Cu on the chalcogen glass layer. This member gave a good result as a photosensitive member for a phase hologram as well as in Examples 1 and 2.

EXAMPLE 4 As Se Te, was vapor-deposited on a highly flat glass plate in the thickness of about 0.5 microns and silver layer of about 20 millimicrons thick was formed thereon. The resulting member was used for conducting a real time holography as shown in FIG. 31, and the state and amount ofa small deformation on a body 16 caused by an external force 17 was directly determined. The interference pattern is shown in FIG. 32.

The optical system in FIG. 31 comprises argon laser 5 (wavelength 4880A, output power 500 mW), shutter 18, beam expander 6, plane reflection mirror 19, surface to be measured 20, beam splitter 7, the abovementioned photosensitive member 9, He Ne laser 21 (wavelength 6328A), primary diffraction light 22, camera for photographing an interference pattern 24, interference filters 23, 23 (for 6328A), primary diffraction light 22, mask 30, and photoelectron multiplier 33. The photoelectron multiplier 33 is used for measuring the intensity of diffraction light to indicate the regeneration efficiency and the shutter 18 closes'when the regeneration efficiency is maximum. Therefore, laser 21 serves as a monitor for giving an optimum exposure. When the exposure before the deformation of body surface 20 became almost sufficient, an external force 17 is applied to deform the surface 20. At this time a light from laser was weakened and a light of laser 21 was cut to observe an interference pattern showing the deformation. The pattern thus observed is the interference pattern in FIG. 32.

The above-mentioned hologram member was soaked in a l percent aqueous solution of Fe (N09 for 5 seconds to completely remove the silver layer and fix. Then, in place of He Ne laser, there was used argon laser and an efficient and light regeneration could be effected for a long time. Further, this member was etched with a 0.5 N aqueous solution of NaOH to form a relief pattern in a non-linear relation with a hologram pattern light intensity. The etching in this case corresponds to a non-linear development.

The relief phase hologram thus obtained shows a diffraction light of high order, and when a phase amplitude method utilizing interference between diffraction waves of high order was carried out, there was easily obtained an interference pattern corresponding to that having an interference fringe distance of A/lO (wave length of light 1/10), and a deformation corresponding to M100 was easily measured. When a silver salt emulsion is used, there is usually a shrinkage of the emulsion layer of about 2 microns and therefore the limit of the phase amplitude method has been considered to be within A/lOO. However. according to the present invention, a minor change such as from )t/lOO to M1000, or a change smaller than such values may be measured.

EXAMPLE 5 H6. 33 shows an optical system for producing a Fourier transformation hologram. The optical system comprises argon laser 5. beam splitter 7, reflection mirror 19, objective lens of microscope 25, pin hole 26, collimator lens 27. transparent positive microfilm 28, filed lens 29, mask 30, photosensitive member according to the present invention 31 and a fine adjusting device 32. Forcal length of lens is designated as forj. An image contained in a transparent positive microfilm corresponds to an image in one page of magazine. When a Fourier transformation holography was effected with respect to such a transparent image, the diffraction light is weak and a light directly incident upon the photosensitive member is very strong and therefore, it is difficult to form a hologram unless the dynamic range of the photosensitive member is sufficiently wide, and it is not usable in case of silver salt emulsion, but according to the present invention, hologram can be produced in such case and high density information recording can be made.

The photosensitive member used in this Example was composed of a flat glass plate, an AS S31Te3 layer of about one micron thick and a copper layer of about 40 millimicrons in thickness and the fixation was effected by soaking in a 2 percent aqueous solution of ammonium persulfate for seconds. to form hologram.

EXAMPLE 6 tion, and etching in a way similar to Example 4 to form a hologram of relief pattern, and then a thermoplastic film (for example, polystyrene and vinyl polymer softened at 100 l50C) was pressed to the relief pattern of hologram was used for \Q? I .20... bypassing between heat rollers to transfer the relief pattern to a thermoplastics. The resulting reproduction generating the image with good result.

EXAMPLE 7 The procedure in Example 6 was repeated except that a copper foil was adhered to a polyester film in place of triacetate film and a low melting chalcogen glass of As Se Te containing 20 percent by weight of iodine was melt-coated on the copper foil. After exposure, a chalcogen glass layer was removed from the copper foil to produce a relief pattern corresponding to the exposure pattern on the copper foil.

The-resulting relief pattern was transferred to a transparent filmto reproduce the hologram in a way similar to Example 6;-

EXAMPLE 8 As a chalcogen glass layer and a metal layer, there were used As Se Ge, and an alloy of Cu Ag respectively.

The resulting member was exposed to a hologram pattern while the member was heated by an infrared lamp from the side. When the member was heated to about C, the necessary exposure energy decreases to about one tenth, that is, from about 10 erg/cm to l0 erg/cm This member was of low sensitivity, but,

the mechanical strength was very strong.

EXAMPLE 9 The silver layer was removed to produce a good phase hologram.

EXAMPLE 10 A layer of Pblg was formed by vapor-depositing on a glass plate and then a layer of alloy consisting of Af( 30) and ln(70) was formed on the coated plate (the numbers being in parentheses show each weight percent). By using the member, a hologram having a high resolving power was prepared and a good holography was regenerated.

EXAMPLE 1 l A member prepared by forming a layer of chalcogen glass consisting of As Te S on a glass plate and furthermore forming a layers of Ag on the chalcogen layer was exposed to an energy of 10 erg/cm The member could be exposed at an exposure time of about l/lOO second by argon laser, so that a good hologram was obtained even if a shock absorbing bed was not used.

EXAMPLE 12 A block AgS Te layer containing dispersed Ag was cut by a wire cutter, ground to thickness of about millimicrons, and etched slightly with a weak alkaline solution. Furthermore, the member was exposed to a light of 4880A and thereafter was regenerated by a EXAMPLE 13 A layer of A 5 was coated by vacuum evaporation coating in thickness of 200 millimicrons on a glass plate (The degree of vacuum was 5 X Torr. and the temperature ofthe glass plate was l50C), and then Ag was applied to the layer of AS253 by vacuum evaporation coating in thickness of about millimicrons to produce a photosensitive member. After hologram exposure by a usual way, the remaining metals were removed by a chromic acid mixture (H 30 K Cr O and the layer of As S at an unexposed portion was removed by an alcoholic solution of 0.5 N sodium hydroxide. The hologram pattern was formed at the exposed portion of the glass plate. After the pattern was converted to a strong acid resist layer, the glass plate was etched with hydrofluoric acid and the resist layer against strong acids was removed by dipping in a chromic acid mixture for a long time and a relieved glass plate was obtained. This relieved glass plate was an almost complete phase hologram and showed a diffraction efficiency as high as about 30 percent. The hologram is mechanically strong, durable and chemical resistant.

EXAMPLE l4 A dry plate of high resolving power produced by a silver salt emulsion 649F(supplied by KODAK) was exposed to a hologram pattern according to a conventional method and developed to form an amplitude hologram. The resulting hologram was closely contacted with a photosensitive member composed of a glass plate, a chalcogen layer of As ,Se,,-,Ge .,S, of 300 millimicrons thick, and a silver layer of 20 millimicrons thick, and exposed to a light of a xenon lamp to print a hologram pattern.

The exposure amounts ranged from about 10 lux. sec, to if) lux. sec. and almost similar results were obtained. There occurred no irregularity as fomed in case of phase hologram by bleaching of silver salt emulsion, butthere was obtained a stable and highly reproducible result.

The member printed as mentioned above was soaked in an aqueous solution of ferric chloride to remove the silver layer. The resulting hologram had a higher surface strength and durability than a hologram of silver salt emulsion. Further, the above mentioned member was etched with a 0.3N alcoholic solution of NaOH to remove the unexposed portion and produce a relief pattern. this relief pattern was used as a master hologram and heated to about 100C and then a warm polystyrene film was pressed thereonto by a roller to trans- 22 fer the relief pattern to the polystyrene film. Thus, many reproduced holograms were produced.

We claim:

l. A hologrampreparcd by irradiating an interference pattern on a photosensitive member having a photosensitive layer, a laminate ofa photoconductive layer and a metal layer, the photoconductive layer being mainly composed of at least a photoconductive material selected from the group ofchalcogen glass ofglassy material containing a sulfur family element (S, Se, Te), organic photoconductive materials, metal halides, metal sulfides, metal selenide, metal telluride, and metal oxide and the metal layer being mainly composed of metal which diffuses into the photoconductive layer when exposed to light radiation and by causing the diffusion of metal in the photoconductive layer at the exposed portion of the photosensitive member.

2. A hologram according to claim 1 in which the irradiation of an interference pattern is carried out by exposure to an original pattern having an interference pattern capable of being used as a hologram.

3. A hologram according to claim 1 in which the chalcogen glass contains halogen.

4. A hologram prepared by irradiating an interference pattern containing recorded information on a photosensitive member having, as a photosensitive layer, a laminate of a photoconductive layer and a metal layer, the photoconductive layer being mainly composed of at least a photoconductive material selected from the group of chalcogen glass of glass material containing a sulfur family element (S, Se, Te), organic photoconductive materials, metal halides, metal sulfides, metal selenide, metal telluride, and metal oxide and the metal layer being mainly composed of metal which diffuses into the photoconductive layer when exposed to light radiation and by causing the diffusion of metalin the photoconductive layer at the exposed portion of the photosensitive member and thereafter by removing at least one of the metal layer and the photoconductive layer which do not contribute to the formation of the diffused portion to form a relief.

5. A hologram prepared by irradiating an interference pattern containing recorded information on a photosensitive member having, as a photosensitive layer, a laminate of a photoconductive layer and a metal layer, the photoconductive layer being mainly composed of at least a photoconductive material selected from the group of chalcogen glass of glassy material containing a sulfur family element (S, Se, Te), organic photoconductive materials, metal halides, metal sulfides, metal selenide, metal telluride, and metal oxide and the metal layer being mainly composed of metal which diffuses into the photoconductive layer when exposed to light radiation and by causing the diffusion of metal in the photoconductive layer at the exposed portion of the photosensitive member and thereafter by removing the mutual diffusion portion thus prepared to form a relief.

6. A hologram according to claim 5 in which after removing the mutual diffusion portion, the metal at the unexposed portion is diffused in the photoconductive layer by exposing the whole surface to light irradiation.

7. A hologram according to claim 5 in which the 8. A hologram according to claim in which the photoconductive layer at the unexposed portion is removed by dissolving after removing the mutual diffusion portion.

9. A hologram prepared by transferring the original relief of the hologram in claims 5 to a transfer member by press transferring.

10. A hologram prepared by transferring the original reliefof the hologram in claim 8 to a transferring member by press-transferring.

11. A hologram prepared by irradiating an interference pattern containing recorded information on a photosensitive member having, as a photosensitive layer, a laminate of a photoconductive layer and a metal layer, the photoconductive layer being mainly composed of at least a photoconductive material selected from the group of chalcogen glass of glassy material containing a sulfur family element (S, Se, Te), organic photoconductive materials, metal halides, metal sulfides, metal selenide, metal telluride, and metal oxide and the metal layer being mainly composed of metal which diffuses into the photoconductive layer when exposed to light radiation and by causing diffusion of metal in the photoconductive layer at the exposed portion of the photosensitive member and thereafter by removing the photosensitive layer at the unexposed portion and further etching the unexposed portion of the base supporting the photosensitive layer to form a relief.

12. A hologram according to claim 11 in which the mutual diffusion portion-is removed after etching the surface of the base at the unexposed portion.

13. A hologram according to claim 11 in which a reliefofthe hologram in claim 11 is transferred to a transferring member by press-transferring.

l4. Ahologram according to claim 12 in which a relief of the hologram in claim 12 is transferred to a transferring member by press-transferring.

15. A hologram prepared by irradiating an interference pattern containing recorded information on a photosensitive member having, as a photosensitive layer, a laminate of a photoconductive layer and a metal layer, the photoconductive layer being mainly composed of at least a photoconductive material selected from the group of chalcogen glass of glassy material containing a sulfur family element (S, Se, Te), organic photoconductive materials, metal halides, metal sulfides, metal selenide, metal telluride, and metal oxide and the metal layer being mainly composed of metal which diffuses into the photoconductive layer when exposed to light radiation and by causing the diffusion of metal in the photoconductive layer at the exposed portion of the photosensitive member and thereafter by peeling off the exposed portion to expose the surface of the base supporting the photo-sensitive layer and by etching the exposed portion to form a relief and, if desired, by removing at least one of the metal layer and the photosensitive layer at the unexposed portion by dissolving.

16. A hologram according to claim 15 in which the formed relief of the hologram is transferred to a transferring member by press-transferring.

17. A hologram according to claim 15 in which the metal at the unexposed portion is diffused in the photoconductive layer by exposing the whole surface thereof to light irradiation after peeling off the exposed portron.

. UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTEG'N Patent No. 825 r 317 Dated July 23. 1974 Invent -(s) EIICHI INOUE ET AL It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[30] Foreign Application Priority Data:

July 28, M71 Japan 56642 August 23,1971 Japan 64268 Column 2, line 55, "shov l" should read --shows--; Column 3, line 32, "This interference" should-read Q --This interference-; in

Column 3, line 46, "The nutual diffusion" should read --The mutual diffusion-;

Column 3, line 48, "radiation different" should read radiation is different--;

Column 7, line, 31,v "3" should read --3 '1--; Colunm 10, line 10, "patterns" should read -pattern;

Column 10, line 34, "shows" should read -show-;

Column 11, line 67, "Fig. 10" should read -Fig.l-;-

Column 14, line 52, "considrered" should read -considered-;

FORM PO-105O (10-69) USCOMM-DC seam-Pas W U.S. GOVERNMENT PRINTING OFFICE l9! O355-334,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTEQN pa 3,825,317 Dated July 23, 1974 EIICHI INOUE ET AL Inventor(s) It is certified thaf error appears-in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 16, line 54, "effect or" should read -effect of-;

Column 17, line 53, "AG" should read -Ag--;

Signed and sealed this 26th day of November 1974.

(SEAL) Attest:

McCOY M. GIBS-ON JR. c. MARSHALL DANN Attesting Offieer Commissioner of Patents FORM po'wso v uscoMM-oc 60376-P69 U.5. GOVERNMENT IdRlNTlNG OFFICE 1969 0-366-334,

Claims

2. A hologram according to claim 1 in which the irradiation of an interference pattern is carried out by exposure to an original pattern having an interference pattern capable of being used as a hologram.
3. A hologram according to claim 1 in which the chalcogen glass contains halogen.
4. A hologram prepared by irradiating an interference pattern containing recorded information on a photosensitive member having, as a photosensitive layer, a laminate of a photoconductive layer and a metal layer, the photoconductive layer being mainly composed of at least a photoconductive material selected from the group of chalcogen glass of glass material containing a sulfur family element (S, Se, Te), organic photoconductive materials, metal halides, metal sulfides, metal selenide, metal telluride, and metal oxide and the metal layer being mainly composed of metal which diffuses into the photoconductive layer when exposed to light radiation and by causing the diffusion of metal in the photoconductive layer at the exposed portion of the photosensitive member and thereafter by removing at least one of the metal layer and the photoconductive layer which do not contribute to the formation of the diffused portion to form a relief.
5. A hologram prepared by irradiating an interference pattern containing recorded information on a photosensitive member having, as a photosensitive layer, a laminate of a photoconductive layer and a metal layer, the photoconductive layer being mainly composed of at least a photoconductive material selected from the group of chalcogen glass of glassy material containing a sulfur family element (S, Se, Te), organic photoconductive materials, metal halides, metal sulfides, metal selenide, metal telluride, and metal oxide and the metal layer being mainly composed of metal which diffuses into the photoconductive layer when exposed to light radiation and by causing the diffusion of metal in the photoconductive layer at the exposed portion of the photosensitive member and thereafter by removing the mutual diffusion portion thus prepared to form a relief.
6. A hologram according to claim 5 in which after removing the mutual diffusion portion, the metal at the unexposed portion is diffused in the photoconductive layer by exposing the whole surface to light irradiation.
7. A hologram according to claim 5 in which the metal layer is removed by dissolving after removing the mutual diffusion portion.
8. A hologram according to claim 5 in which the photoconductive layer at the unexposed portion is removed by dissolving after removing the mutual diffusion portion.
9. A hologram prepared by transferring the original relief of the hologram in claims 5 to a transfer member by press-transferring.
10. A hologram prepared by transferring the original relief of the hologram in claim 8 to a transferring member by press-transferring.
11. A hologram prepared by irradiating an interference pattern containing recorded information on a photosensitive member having, as a photosensitive layer, a laminate of a photoconductive layer and a metal layer, the photoconductive layer being mainly composed of at least a photoconductive material selected from the group of chalcogen glass of glassy material containing a sulfur family element (S, Se, Te), organic photoconductive materials, metal halides, metal sulfides, metal selenide, metal telluride, and metal oxide and the metal layer being mainly composed of metal which diffuses into the photoconductive layer when exposed to light radiation and by causing diffusion of metal in the photoconductive layer at the exposed portion of the photosensitive member and thereafter by removing the photosensitive layer at the unexposed portion and further etching the unexposed portion of the base supporting the photosensitive layer to form a relief.
12. A hologram according to claim 11 in which the mutual diffusion portion is removed after etching the surface of The base at the unexposed portion.
13. A hologram according to claim 11 in which a relief of the hologram in claim 11 is transferred to a transferring member by press-transferring.
14. A hologram according to claim 12 in which a relief of the hologram in claim 12 is transferred to a transferring member by press-transferring.
15. A hologram prepared by irradiating an interference pattern containing recorded information on a photosensitive member having, as a photosensitive layer, a laminate of a photoconductive layer and a metal layer, the photoconductive layer being mainly composed of at least a photoconductive material selected from the group of chalcogen glass of glassy material containing a sulfur family element (S, Se, Te), organic photoconductive materials, metal halides, metal sulfides, metal selenide, metal telluride, and metal oxide and the metal layer being mainly composed of metal which diffuses into the photoconductive layer when exposed to light radiation and by causing the diffusion of metal in the photoconductive layer at the exposed portion of the photosensitive member and thereafter by peeling off the exposed portion to expose the surface of the base supporting the photo-sensitive layer and by etching the exposed portion to form a relief and, if desired, by removing at least one of the metal layer and the photosensitive layer at the unexposed portion by dissolving.
16. A hologram according to claim 15 in which the formed relief of the hologram is transferred to a transferring member by press-transferring.
17. A hologram according to claim 15 in which the metal at the unexposed portion is diffused in the photoconductive layer by exposing the whole surface thereof to light irradiation after peeling off the exposed portion.