US20040190828A1 - Wavelength tunable filter device for fiber optic systems - Google Patents

Wavelength tunable filter device for fiber optic systems Download PDF

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Publication number
US20040190828A1
US20040190828A1 US10/821,954 US82195404A US2004190828A1 US 20040190828 A1 US20040190828 A1 US 20040190828A1 US 82195404 A US82195404 A US 82195404A US 2004190828 A1 US2004190828 A1 US 2004190828A1
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United States
Prior art keywords
optical
fiber
support block
optical signal
bragg grating
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Abandoned
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US10/821,954
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Evelyn Boettcher
Sandeep Vohra
Paul Matthews
Paul Biernacki
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Optinel Systems Inc
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Optinel Systems Inc
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Priority to US10/821,954 priority Critical patent/US20040190828A1/en
Assigned to OPTINEL SYSTEMS, INC. reassignment OPTINEL SYSTEMS, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BIERNACKI, PAUL D., BOETTCHER, EVELYN, MATTHEWS, PAUL J., VOHRA, SANDEEP T.
Publication of US20040190828A1 publication Critical patent/US20040190828A1/en
Abandoned legal-status Critical Current

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
    • G02B6/29316—Light guides comprising a diffractive element, e.g. grating in or on the light guide such that diffracted light is confined in the light guide
    • G02B6/29317—Light guides of the optical fibre type
    • G02B6/29319—With a cascade of diffractive elements or of diffraction operations
    • G02B6/2932—With a cascade of diffractive elements or of diffraction operations comprising a directional router, e.g. directional coupler, circulator
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
    • G02B6/29316—Light guides comprising a diffractive element, e.g. grating in or on the light guide such that diffracted light is confined in the light guide
    • G02B6/29317—Light guides of the optical fibre type
    • G02B6/29322—Diffractive elements of the tunable type
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29379—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device
    • G02B6/29395—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device configurable, e.g. tunable or reconfigurable
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/27—Optical coupling means with polarisation selective and adjusting means
    • G02B6/2753—Optical coupling means with polarisation selective and adjusting means characterised by their function or use, i.e. of the complete device
    • G02B6/278—Controlling polarisation mode dispersion [PMD], e.g. PMD compensation or emulation
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29379—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device
    • G02B6/2938—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM
    • G02B6/29382—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM including at least adding or dropping a signal, i.e. passing the majority of signals
    • G02B6/29383—Adding and dropping
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29379—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device
    • G02B6/29392—Controlling dispersion
    • G02B6/29394—Compensating wavelength dispersion

Definitions

  • This invention relates to devices for use in optical communication systems. More specifically, it relates to tunable filters for optical communications systems.
  • WDM wavelength division multiplexed
  • Desired device characteristics include a well-defined passband and a small insertion loss. Chromatic and polarization-mode dispersion attributable to the filter should also be minimized.
  • a grating reflects light in a well-defined, narrow bandwidth centered around a wavelength directly related to the period of the grating.
  • Such a device may be used as a tunable filter if the grating period can be controllably and reversibly altered. This has been accomplished in the past with such methods as the application of heat to a material rigidly attached to the grating fiber, with the subsequent thermally induced strain to the grating and temperature dependent changes in the refractive index altering the grating period, and thus shifting the reflected waveband peak.
  • One drawback to such an approach is a relatively slow response time.
  • a copending patent application commonly assigned to the same assignee as this application describes a tunable dispersion compensating device in which a fiber Bragg grating is embedded in a compliant material at an angle to a load-bearing surface (“Tunable Dispersion Compensating Bandwidth Device for Fiber Optic System,” Application No. 09/957,022 filed Sep. 21, 2001), the entire contents of which is incorporated herein by reference.
  • a non-linear strain results from an applied load on the load bearing surface to result in a chirped Bragg grating within the fiber.
  • a wavelength tunable filter device for fiber optic systems has a compliant support block that has a longitudinal axis and a load-receiving surface oriented substantially orthogonal to the longitudinal axis.
  • the load receiving surface is capable of receiving a load substantially orthogonal to said surface.
  • the device also has a portion of fiber containing a Bragg grating disposed in the compliant support block and extending substantially along, and at an angle to said longitudinal axis.
  • a wavelength division multiplexed optical communication system has a plurality of optical transmitters, an optical multiplexer in optical communication with the plurality of optical transmitters, a signal transmission waveguide in optical communication with the optical multiplexer, a wavelength tunable optical filter unit in optical communication with the signal transmission waveguide, an optical demultiplexer in optical communication with the signal transmission waveguide, and a plurality of receivers in communication with the demultiplexers.
  • the wavelength tunable optical filter unit has a compliant support block having a longitudinal axis and a load-receiving surface oriented substantially orthogonal to the longitudinal axis.
  • the load-receiving surface is suitable to receive an applied load in a direction substantially parallel to the longitudinal axis.
  • a portion of fiber containing a Bragg grating is disposed in the compliant support block and extends substantially along, and at an angle to, the longitudinal axis of the compliant support block.
  • a method of making a wavelength tunable optical filter device for optical communications systems includes disposing a portion of fiber containing a Bragg grating into a cylindrical mold, pouring support material into the cylindrical mold, said support material being compliant when it sets, and attaching a load-supplying assembly to a top surface of the support material.
  • FIG. 1 is a schematic illustration of a wavelength-tunable optical filter according to an embodiment of the invention
  • FIG. 2 is a schematic illustration of a wavelength-tunable optical filter according to an embodiment of the invention wherein glass microspheres are dispersed within the compliant support block;
  • FIG. 3 shows the reflection spectra of a wavelength-tunable optical filter unit, according to an embodiment of the invention, for several values of applied load
  • FIG. 4 is a plot of applied load, as related to micrometer setting, as a function of the reflected wavelength peak for a wavelength tunable optical filter unit according to an embodiment of the invention
  • FIG. 5 is a schematic illustration of an optical add/drop multiplexer which utilizes a plurality of wavelength tunable optical filters according to the present invention.
  • FIG. 6 is a schematic illustration of a wavelength division multiplexed optical communication system which utilizes a wavelength tunable optical filter unit according to an embodiment of the invention.
  • optical and light are used in a broad sense in this description to include both visible and non-visible regions of the electromagnetic spectrum.
  • infrared light is used extensively in transmitting signals in optical communications systems. Infrared light is included within the broad meaning of the term light as used herein.
  • FIG. 1 is a schematic illustration of an embodiment of the invention.
  • a wavelength-tunable optical filter 110 has a cylindrically shaped compliant support block 112 that has a longitudinal axis 114 and a load-receiving surface 116 oriented substantially orthogonal to the longitudinal axis 114 .
  • a portion of optical fiber 118 having at least a section with a fiber Bragg grating written therein is disposed within the cylindrically shaped compliant support block 112 , a fiber Bragg grating being a length of optical fiber along which the refractive index varies periodically and which reflects light in a narrow wavelength band centered about a wavelength directly related to the periodicity.
  • said portion of optical fiber 118 is wrapped around a pre-set cylindrical or conically shaped piece 130 .
  • the cylindrical support block 112 is placed within a support frame 120 .
  • the side of said cylindrical support block 112 is left exposed so as to allow for expansion on application of an applied load in a direction substantially parallel to the longitudinal axis of the cylinder.
  • a machined fixture 122 suitable to hold a micrometer screw assembly, is attached to the support frame.
  • a rigid plate 124 is placed proximate to one end face of said cylindrical support block 112 .
  • a micrometer screw assembly 126 is attached to the machined fixture 122 proximate to the rigid plate 124 .
  • a micrometer screw 128 is in contact with the rigid circular plate 124 , and oriented substantially parallel to the longitudinal axis 114 of the cylindrical support block 112 .
  • the support block 112 is composed of a material which may be compressed or stretched by an applied force in a substantially reversible fashion, such that its initial shape is substantially restored on removal of the applied force.
  • Suitable materials from which to make the compliant support block 112 include elastic and visco-elastic polymers, but are not limited to those materials.
  • glass microspheres 210 may be dispersed within the compliant support block 112 in order to alter the mechanical properties of the block.
  • the compliant support block 112 is fabricated by pouring the selected support block material into a cylindrical mold within which said portion of fiber 118 containing the fiber Bragg grating is held in place. This may be accomplished by wrapping said portion of fiber 118 containing the fiber Bragg grating around said pre-set cylindrical or conically shaped piece 130 , or other suitably shaped piece, comprised of the material of which the compliant support block is to be made. Said portion of fiber 118 containing the fiber Bragg grating may then be held in place on the piece around which it is wrapped with a suitable adhesive, and said piece is then inserted into the cylindrical mold before pouring of the support block material into the mold.
  • Said portion of fiber 118 may also be pre-coated with support block material before pouring to assure good adhesion to the fiber.
  • said portion of fiber 118 is wrapped in a spiral fashion, at a fixed pitch and radius, within the compliant support block 112 .
  • the axis of the fiber spiral is coincident with the longitudinal axis of the cylindrical support block 112 .
  • an 8 mm length of fiber was embedded within the support block. The optical fiber enters and exits through the side of the cylindrical support block 112 in the prototype, but other entrance and exit locations are possible.
  • An aluminum alloy is a suitable material for said rigid plate 124 .
  • said plate 124 is not limited to only aluminum alloys.
  • the micrometer screw assembly 126 has one micrometer screw 128 , but the micrometer screw assembly 126 may have a plurality of micrometer screws in other embodiments.
  • the invention functions by adjustment of the micrometer screw 128 to apply a downward variable load to the rigid plate 124 , the direction of the load being substantially parallel to the longitudinal axis of the cylindrical support block 112 and substantially uniform over the area of the cylinder end face.
  • the load is transferred through the rigid plate 118 to the cylindrical support block 112 , resulting in a radial deformation of the cylindrical support block 112 .
  • This deformation produces an axial strain on the embedded portion of fiber 118 , with the exact strain profile dependent on the precise location and orientation of the fiber within the support block 112 .
  • the resultant strain on the embedded portion of fiber 118 causes an expansion in the period of the Bragg grating contained therein, and thus an upward shift in the Bragg wavelength of the device.
  • the applied load may be generated in any number of ways, including a stepper motor, a DC motor, piezoelectric elements, etc., instead of a micrometer(s).
  • the invention may be configured such that the portion of fiber containing a Bragg grating is subject to a compressive force. As optical fibers are more tolerant of compression, this may lead to larger tuning ranges.
  • the invention may be used in either a transmission or reflection mode, with no restrictions as to how the signal is routed, including the use of a circulator.
  • FIG. 4 is a graph of the Bragg reflection peak as a function of micrometer setting.
  • a wavelength tunable optical filtering device may be installed at various points within an optical communication system. Such a device may be used as a dynamic channel selector in a WDM system, as part of a reconfigurable optical add-drop multiplexer, or as a component in an optical monitor; but would not be limited to those applications.
  • FIG. 5 shows a schematic representation of an add-drop multiplexer 500 which utilizes wavelength tunable optical filters according to an embodiment of the present invention.
  • the incoming signal 502 containing a plurality of wavelengths, enters interleaver 504 and exits interleaver 504 split into optical signal path 506 and optical signal path 508 .
  • Each optical signal enters a separate circulator.
  • Optical signal path 506 enters first circulator 510 at port 512 and exits at port 514 to be directed into path 516 .
  • In path 516 are disposed a series of tunable fiber-Bragg grating assemblies 517 A, 517 B, 517 C, etc. for selecting respectively wavelength ⁇ 11 , ⁇ 12 and ⁇ 13 .
  • Each tunable fiber Bragg grating assembly may be a tunable fitter according to the invention such as the tunable filter 110 . While three Bragg gratings are shown in path 516 , it is understood that there can be one grating, two or more gratings.
  • Each fiber Bragg grating is configured to reflect a portion of optical wavelengths, included in the wavelength division multiplexed optical communication signal, to circulator port 514 while transmitting the remaining wavelengths, that is wavelengths other than ⁇ 11 , ⁇ 11 and ⁇ 13 .
  • the wavelengths being transmitted correspond to the optical channels to be dropped while the wavelengths reflected towards circulator port 514 , to be output by circulator 510 through the optical port 518 , correspond to the through channel.
  • optical signal path 508 enters second circulator 520 at port 522 and exits at port 524 to be directed into path 526 .
  • path 526 are disposed a series of fiber-Bragg gratings 527 A, 527 B, 527 C for selecting respectively wavelength ⁇ 21 , ⁇ 22 , ⁇ 23 . While three Bragg gratings are shown in path 526 , it is understood that that there can also be one grating, two or more than three gratings.
  • Each fiber Bragg grating is configured to reflect a portion of optical wavelengths included in the wavelength division multiplexed optical communication signal to circulator port 524 while transmitting the remaining wavelengths, that is wavelengths other than ⁇ 21 , ⁇ 22 , ⁇ 23 .
  • the wavelengths being transmitted correspond to the optical channels to be dropped while the wavelengths reflected towards circulator port 524 , to be output by circulator 520 through the optical port 528 , correspond to the through channel.
  • Optical path 519 optically communicating with the third circulator port 518 , is configured to receive optical wavelengths output by the third circulator port 518 corresponding to the channels not dropped from the wavelength division multiplexed optical communication signal in path 506 .
  • the channels in the optical path 519 consisting of ⁇ 11 , ⁇ 12 , and ⁇ 13 correspond to the through channels.
  • Optical path 529 optically communicating with the third circulator port 528 , is configured to receive optical wavelengths output by the third circulator port 528 corresponding to the channels not dropped from the wavelength division multiplexed optical communication signal in path 508 .
  • the channels in the optical path 529 consisting of ⁇ 21 , ⁇ 22 , and ⁇ 23 correspond to the through channels.
  • Optical path 519 connected to the third optical port of the first circulator 510 carrying wavelengths ⁇ 11 , ⁇ 12 , and ⁇ 13 and optical path 529 connected to the third optical port of the second circulator 520 carrying wavelengths ⁇ 21 , ⁇ 22 , and ⁇ 23 are connected to processing unit 530 comprising optical amplification, channel equalization, recombination and addition.
  • Processing unit 530 amplifies, equalizes, combines and adjusts the two signals carried by the two paths 519 and 529 .
  • the optical channel control unit 540 allows for maintaining the fiber Bragg grating within the band guard for selecting the desired wavelengths.
  • channel-monitoring unit 540 allows for precise wavelength monitoring and feedback to tuning elements as described previously.
  • the reconfigurable add/drop multiplexer illustrated demonstrates both flexibility and scalability. It is shown that two optical signals can be treated at the same time, and more than two optical signals can be treated in this way by splitting the incoming optical signal into more optical sub-signals and adding circulators and fiber Bragg grating lines to select wavelengths in each optical sub-signal.
  • FIG. 6 is a schematic illustration of a wavelength division multiplexed optical communication system 600 that utilizes a wavelength tunable optical filter unit 110 according to an embodiment of the invention.
  • the wavelength division multiplexed optical communication system 600 has a plurality of optical transmitters 602 , an optical multiplexer 604 in communication with the plurality of optical transmitters 602 , a signal transmission waveguide 606 in optical communication with the optical multiplexer 604 , an optical demultiplexer 608 in optical communication with the signal transmission waveguide 606 and a plurality of receivers 610 in optical communication with the optical demultiplexer.
  • the wavelength tunable optical filter unit 110 may be inserted at various points within the optical communication system 600 , such as along the path of the signal transmission waveguide 606 , at either end of the signal transmission waveguide 606 , between any one of the optical transmitters 602 and optical multiplexer 604 , or between any one of the optical receivers 610 and the optical demultiplexer 608 .
  • FIG. 6 illustrates the example in which the wavelength tunable optical filter unit 110 is inserted along the path of the signal transmission waveguide 606 .
  • One may also include more than one wavelength tunable optical filter unit within an optical communication system, as needed.

Abstract

A wavelength tunable filter for optical communication systems has an optical fiber containing a Bragg grating disposed within a compliant support block. A length of the fiber is wrapped in a spiral of fixed pitch around the longitudinal axis of a cylindrical polymer support block. The support block is placed within a support frame to which a micrometer screw assembly is attached and oriented to apply a variable mechanical load substantially parallel to the longitudinal axis of the cylindrical support block. Application of the load introduces a strain on the support block, changing the period of the refractive index in the fiber Bragg grating with a resulting shift in the Bragg reflection peak.

Description

    BACKGROUND
  • 1. Field of Invention [0001]
  • This invention relates to devices for use in optical communication systems. More specifically, it relates to tunable filters for optical communications systems. [0002]
  • 2. Discussion of Related Art [0003]
  • The current trend towards increased channel density in wavelength division multiplexed (WDM) optical communication systems, with increasing numbers of channels per fiber and increasingly narrow channel bandwidths, has intensified the need for simple, efficient methods to precisely control signal flow and content. A basic requirement for this technology is the availability of a tunable optical filter. Such a device may be used as a dynamic channel selector in a WDM system, as part of a reconfigurable optical add-drop multiplexer, or as a component in an optical monitor. Desired device characteristics include a well-defined passband and a small insertion loss. Chromatic and polarization-mode dispersion attributable to the filter should also be minimized. [0004]
  • Conventional fiber Bragg gratings are commonly used in fiber optic systems for selectively controlling and modifying specific wavelength bands of light. A grating reflects light in a well-defined, narrow bandwidth centered around a wavelength directly related to the period of the grating. Such a device may be used as a tunable filter if the grating period can be controllably and reversibly altered. This has been accomplished in the past with such methods as the application of heat to a material rigidly attached to the grating fiber, with the subsequent thermally induced strain to the grating and temperature dependent changes in the refractive index altering the grating period, and thus shifting the reflected waveband peak. One drawback to such an approach is a relatively slow response time. Others have employed piezoelectric actuators attached to the portion of fiber containing the Bragg grating in such a fashion as to stretch it on application of an applied voltage. The strain produced by piezoelectric actuation however, is relatively small, which limits the tuning range of the device. Another potential disadvantage of this method is the need for continuous application of relatively high voltages. [0005]
  • A copending patent application commonly assigned to the same assignee as this application describes a tunable dispersion compensating device in which a fiber Bragg grating is embedded in a compliant material at an angle to a load-bearing surface (“Tunable Dispersion Compensating Bandwidth Device for Fiber Optic System,” Application No. 09/957,022 filed Sep. 21, 2001), the entire contents of which is incorporated herein by reference. In that device, a non-linear strain results from an applied load on the load bearing surface to result in a chirped Bragg grating within the fiber. [0006]
    • SUMMARY
  • A wavelength tunable filter device for fiber optic systems has a compliant support block that has a longitudinal axis and a load-receiving surface oriented substantially orthogonal to the longitudinal axis. The load receiving surface is capable of receiving a load substantially orthogonal to said surface. The device also has a portion of fiber containing a Bragg grating disposed in the compliant support block and extending substantially along, and at an angle to said longitudinal axis. [0007]
  • A wavelength division multiplexed optical communication system has a plurality of optical transmitters, an optical multiplexer in optical communication with the plurality of optical transmitters, a signal transmission waveguide in optical communication with the optical multiplexer, a wavelength tunable optical filter unit in optical communication with the signal transmission waveguide, an optical demultiplexer in optical communication with the signal transmission waveguide, and a plurality of receivers in communication with the demultiplexers. [0008]
  • The wavelength tunable optical filter unit has a compliant support block having a longitudinal axis and a load-receiving surface oriented substantially orthogonal to the longitudinal axis. The load-receiving surface is suitable to receive an applied load in a direction substantially parallel to the longitudinal axis. A portion of fiber containing a Bragg grating is disposed in the compliant support block and extends substantially along, and at an angle to, the longitudinal axis of the compliant support block. [0009]
  • A method of making a wavelength tunable optical filter device for optical communications systems includes disposing a portion of fiber containing a Bragg grating into a cylindrical mold, pouring support material into the cylindrical mold, said support material being compliant when it sets, and attaching a load-supplying assembly to a top surface of the support material.[0010]
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • These and other objects and advantages of the invention will become more apparent and more readily apparent and more readily appreciated from the following detailed description of the presently preferred exemplary embodiments of the invention, taken in conjunction with the accompanying drawings, of which: [0011]
  • FIG. 1 is a schematic illustration of a wavelength-tunable optical filter according to an embodiment of the invention; [0012]
  • FIG. 2 is a schematic illustration of a wavelength-tunable optical filter according to an embodiment of the invention wherein glass microspheres are dispersed within the compliant support block; [0013]
  • FIG. 3 shows the reflection spectra of a wavelength-tunable optical filter unit, according to an embodiment of the invention, for several values of applied load; [0014]
  • FIG. 4 is a plot of applied load, as related to micrometer setting, as a function of the reflected wavelength peak for a wavelength tunable optical filter unit according to an embodiment of the invention; [0015]
  • FIG. 5 is a schematic illustration of an optical add/drop multiplexer which utilizes a plurality of wavelength tunable optical filters according to the present invention; and [0016]
  • FIG. 6 is a schematic illustration of a wavelength division multiplexed optical communication system which utilizes a wavelength tunable optical filter unit according to an embodiment of the invention.[0017]
    • DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
  • In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular optical and electrical circuits, circuit components, techniques, etc. in order to facilitate a thorough understanding of the present invention. However, the invention may be practiced in other embodiments that depart from these specific details. The terms optical and light are used in a broad sense in this description to include both visible and non-visible regions of the electromagnetic spectrum. Currently, infrared light is used extensively in transmitting signals in optical communications systems. Infrared light is included within the broad meaning of the term light as used herein. [0018]
  • FIG. 1 is a schematic illustration of an embodiment of the invention. A wavelength-tunable [0019] optical filter 110 has a cylindrically shaped compliant support block 112 that has a longitudinal axis 114 and a load-receiving surface 116 oriented substantially orthogonal to the longitudinal axis 114. A portion of optical fiber 118 having at least a section with a fiber Bragg grating written therein is disposed within the cylindrically shaped compliant support block 112, a fiber Bragg grating being a length of optical fiber along which the refractive index varies periodically and which reflects light in a narrow wavelength band centered about a wavelength directly related to the periodicity. In one embodiment of the invention, said portion of optical fiber 118 is wrapped around a pre-set cylindrical or conically shaped piece 130. The cylindrical support block 112 is placed within a support frame 120. The side of said cylindrical support block 112 is left exposed so as to allow for expansion on application of an applied load in a direction substantially parallel to the longitudinal axis of the cylinder. A machined fixture 122, suitable to hold a micrometer screw assembly, is attached to the support frame. A rigid plate 124 is placed proximate to one end face of said cylindrical support block 112. A micrometer screw assembly 126 is attached to the machined fixture 122 proximate to the rigid plate 124. A micrometer screw 128 is in contact with the rigid circular plate 124, and oriented substantially parallel to the longitudinal axis 114 of the cylindrical support block 112.
  • The [0020] support block 112 is composed of a material which may be compressed or stretched by an applied force in a substantially reversible fashion, such that its initial shape is substantially restored on removal of the applied force. Suitable materials from which to make the compliant support block 112 include elastic and visco-elastic polymers, but are not limited to those materials. In an alternative embodiment, illustrated in FIG. 2, glass microspheres 210 may be dispersed within the compliant support block 112 in order to alter the mechanical properties of the block.
  • In one embodiment the [0021] compliant support block 112 is fabricated by pouring the selected support block material into a cylindrical mold within which said portion of fiber 118 containing the fiber Bragg grating is held in place. This may be accomplished by wrapping said portion of fiber 118 containing the fiber Bragg grating around said pre-set cylindrical or conically shaped piece 130, or other suitably shaped piece, comprised of the material of which the compliant support block is to be made. Said portion of fiber 118 containing the fiber Bragg grating may then be held in place on the piece around which it is wrapped with a suitable adhesive, and said piece is then inserted into the cylindrical mold before pouring of the support block material into the mold. Said portion of fiber 118 may also be pre-coated with support block material before pouring to assure good adhesion to the fiber. In one embodiment said portion of fiber 118 is wrapped in a spiral fashion, at a fixed pitch and radius, within the compliant support block 112. The axis of the fiber spiral is coincident with the longitudinal axis of the cylindrical support block 112. In a prototype of the current invention an 8 mm length of fiber was embedded within the support block. The optical fiber enters and exits through the side of the cylindrical support block 112 in the prototype, but other entrance and exit locations are possible.
  • An aluminum alloy is a suitable material for said [0022] rigid plate 124. However, said plate 124 is not limited to only aluminum alloys.
  • In the described embodiment the [0023] micrometer screw assembly 126 has one micrometer screw 128, but the micrometer screw assembly 126 may have a plurality of micrometer screws in other embodiments.
  • In this embodiment the invention functions by adjustment of the [0024] micrometer screw 128 to apply a downward variable load to the rigid plate 124, the direction of the load being substantially parallel to the longitudinal axis of the cylindrical support block 112 and substantially uniform over the area of the cylinder end face. The load is transferred through the rigid plate 118 to the cylindrical support block 112, resulting in a radial deformation of the cylindrical support block 112. This deformation produces an axial strain on the embedded portion of fiber 118, with the exact strain profile dependent on the precise location and orientation of the fiber within the support block 112. The resultant strain on the embedded portion of fiber 118 causes an expansion in the period of the Bragg grating contained therein, and thus an upward shift in the Bragg wavelength of the device.
  • It should be noted that the applied load may be generated in any number of ways, including a stepper motor, a DC motor, piezoelectric elements, etc., instead of a micrometer(s). [0025]
  • It should also be noted that the invention may be configured such that the portion of fiber containing a Bragg grating is subject to a compressive force. As optical fibers are more tolerant of compression, this may lead to larger tuning ranges. [0026]
  • The invention may be used in either a transmission or reflection mode, with no restrictions as to how the signal is routed, including the use of a circulator. [0027]
  • The reflection spectra of the invention were measured with an optical spectrum analyzer for a range of applied loads. Reflection spectra are shown as a function of micrometer setting in FIG. 3. FIG. 4 is a graph of the Bragg reflection peak as a function of micrometer setting. [0028]
  • A wavelength tunable optical filtering device according to the invention may be installed at various points within an optical communication system. Such a device may be used as a dynamic channel selector in a WDM system, as part of a reconfigurable optical add-drop multiplexer, or as a component in an optical monitor; but would not be limited to those applications. [0029]
  • FIG. 5 shows a schematic representation of an add-[0030] drop multiplexer 500 which utilizes wavelength tunable optical filters according to an embodiment of the present invention. The incoming signal 502, containing a plurality of wavelengths, enters interleaver 504 and exits interleaver 504 split into optical signal path 506 and optical signal path 508. Each optical signal enters a separate circulator. Optical signal path 506 enters first circulator 510 at port 512 and exits at port 514 to be directed into path 516. In path 516 are disposed a series of tunable fiber- Bragg grating assemblies 517A, 517B, 517C, etc. for selecting respectively wavelength λ11, λ12 and λ13. Each tunable fiber Bragg grating assembly may be a tunable fitter according to the invention such as the tunable filter 110. While three Bragg gratings are shown in path 516, it is understood that there can be one grating, two or more gratings. Each fiber Bragg grating is configured to reflect a portion of optical wavelengths, included in the wavelength division multiplexed optical communication signal, to circulator port 514 while transmitting the remaining wavelengths, that is wavelengths other than λ11, λ11 and λ13. The wavelengths being transmitted correspond to the optical channels to be dropped while the wavelengths reflected towards circulator port 514, to be output by circulator 510 through the optical port 518, correspond to the through channel.
  • Similarly, [0031] optical signal path 508 enters second circulator 520 at port 522 and exits at port 524 to be directed into path 526. In path 526 are disposed a series of fiber- Bragg gratings 527A, 527B, 527C for selecting respectively wavelength λ21, λ22, λ23. While three Bragg gratings are shown in path 526, it is understood that that there can also be one grating, two or more than three gratings. Each fiber Bragg grating is configured to reflect a portion of optical wavelengths included in the wavelength division multiplexed optical communication signal to circulator port 524 while transmitting the remaining wavelengths, that is wavelengths other than λ21, λ22, λ23. The wavelengths being transmitted correspond to the optical channels to be dropped while the wavelengths reflected towards circulator port 524, to be output by circulator 520 through the optical port 528, correspond to the through channel.
  • [0032] Optical path 519, optically communicating with the third circulator port 518, is configured to receive optical wavelengths output by the third circulator port 518 corresponding to the channels not dropped from the wavelength division multiplexed optical communication signal in path 506. The channels in the optical path 519, consisting of λ11, λ12, and λ13 correspond to the through channels.
  • Similarly, [0033] Optical path 529, optically communicating with the third circulator port 528, is configured to receive optical wavelengths output by the third circulator port 528 corresponding to the channels not dropped from the wavelength division multiplexed optical communication signal in path 508. The channels in the optical path 529, consisting of λ21, λ22, and λ23 correspond to the through channels.
  • [0034] Optical path 519 connected to the third optical port of the first circulator 510 carrying wavelengths λ11, λ12, and λ13 and optical path 529 connected to the third optical port of the second circulator 520 carrying wavelengths λ21, λ22, and λ23 are connected to processing unit 530 comprising optical amplification, channel equalization, recombination and addition. Processing unit 530 amplifies, equalizes, combines and adjusts the two signals carried by the two paths 519 and 529.
  • The optical [0035] channel control unit 540 allows for maintaining the fiber Bragg grating within the band guard for selecting the desired wavelengths. In other words, channel-monitoring unit 540, allows for precise wavelength monitoring and feedback to tuning elements as described previously.
  • The reconfigurable add/drop multiplexer illustrated demonstrates both flexibility and scalability. It is shown that two optical signals can be treated at the same time, and more than two optical signals can be treated in this way by splitting the incoming optical signal into more optical sub-signals and adding circulators and fiber Bragg grating lines to select wavelengths in each optical sub-signal. [0036]
  • FIG. 6 is a schematic illustration of a wavelength division multiplexed [0037] optical communication system 600 that utilizes a wavelength tunable optical filter unit 110 according to an embodiment of the invention. The wavelength division multiplexed optical communication system 600 has a plurality of optical transmitters 602, an optical multiplexer 604 in communication with the plurality of optical transmitters 602, a signal transmission waveguide 606 in optical communication with the optical multiplexer 604, an optical demultiplexer 608 in optical communication with the signal transmission waveguide 606 and a plurality of receivers 610 in optical communication with the optical demultiplexer. The wavelength tunable optical filter unit 110 may be inserted at various points within the optical communication system 600, such as along the path of the signal transmission waveguide 606, at either end of the signal transmission waveguide 606, between any one of the optical transmitters 602 and optical multiplexer 604, or between any one of the optical receivers 610 and the optical demultiplexer 608. FIG. 6 illustrates the example in which the wavelength tunable optical filter unit 110 is inserted along the path of the signal transmission waveguide 606. One may also include more than one wavelength tunable optical filter unit within an optical communication system, as needed.

Claims (12)

1-12. Cancelled.
13. A method of filtering an optical signal, comprising:
coupling an optical signal into an optical fiber;
receiving a filtered optical signal out of said optical fiber; and
varying a load applied to a compliant support block having at least a portion of said optical fiber embedded therein,
wherein said portion of said optical fiber embedded in said compliant support block has a periodic variation in refractive index along at least a portion thereof to form a fiber Bragg grating in said optical fiber.
14. A method of filtering an optical signal according to claim 13,
wherein said varying said load applied to said compliant support block changes a transmission characteristic of said fiber Bragg grating.
15. A method of filtering an optical signal according to claim 13,
wherein said compliant support block has a substantially cylindrical shape, and
wherein said varying said load applied to said compliant support block comprises changing a compressional force applied between opposing ends of said compliant support block.
16. A method of filtering an optical signal according to claim 13, wherein said filtered optical signal is reflected from said fiber Bragg grating.
17. A method of filtering an optical signal according to claim 13, wherein said filtered optical signal is transmitted through said fiber Bragg grating.
18. Canceled
19. A method of making a tunable optical filter, comprising:
disposing an optical fiber having at least a fiber Bragg grating portion into a substantially cylindrical mold;
pouring support material into a substantially cylindrical mold, said support material being compliant when it sets; and
allowing said support material to set.
20. A method of making a tunable optical filter according to claim 19, further comprising attaching a load-supplying assembly to said support material.
21. A method of making a tunable optical filter according to claim 19, further comprising attaching said optical fiber having said fiber Bragg grating portion to a core of pre-set support material prior to said pouring support material into said substantially cylindrical mold.
22. A method of filtering an optical signal according to claim 13, wherein said optical signal coupled into said optical fiber is a wavelength division multiplexed optical signal having a plurality of signal channels.
23. A method of filtering an optical signal according to claim 22, wherein said filtered optical signal is a single channel selected from said plurality of signal channels.
US10/821,954 2001-12-20 2004-04-12 Wavelength tunable filter device for fiber optic systems Abandoned US20040190828A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060127004A1 (en) * 2004-12-13 2006-06-15 General Dynamics Advanced Information Systems, Inc. System and method for performing dispersion compensation
US20180069635A1 (en) * 2016-09-02 2018-03-08 Adva Optical Networking Se Method and Optical Transmitter Device for Creating an Optical Binary Digital Transmit Signal

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9903450D0 (en) * 1999-02-16 1999-04-07 Oxford Fiber Optic Tools Ltd Wavelength turntable power meter
US6795610B1 (en) * 2002-11-01 2004-09-21 Alliance Fiber Optic Products, Inc. Tunable add-drop filters using two independent optical paths
TWI275849B (en) * 2002-11-29 2007-03-11 Hon Hai Prec Ind Co Ltd Tunable filter device
US6990274B2 (en) * 2003-07-01 2006-01-24 3M Innovative Properties Company Apparatus and method for adjusting the spectral response of an optical waveguide grating
US7006731B2 (en) * 2003-07-01 2006-02-28 3M Innovative Properties Company Apparatus and method for adjusting the spectral response of an optical waveguide grating
GB2556932A (en) * 2016-11-28 2018-06-13 Airbus Operations Ltd A fibre-optic communication system, a communication apparatus for the same, and a vehicle
CN107063648B (en) * 2017-03-10 2019-02-19 北京航空航天大学 A kind of load monitoring method of Intelligent optical fiber grating flange bolt load monitoring device

Citations (85)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4589285A (en) * 1984-11-05 1986-05-20 Western Geophysical Co. Of America Wavelength-division-multiplexed receiver array for vertical seismic profiling
US5022730A (en) * 1989-12-12 1991-06-11 At&T Bell Laboratories Wavelength tunable optical filter
US5042898A (en) * 1989-12-26 1991-08-27 United Technologies Corporation Incorporated Bragg filter temperature compensated optical waveguide device
US5159601A (en) * 1991-07-17 1992-10-27 General Instrument Corporation Method for producing a tunable erbium fiber laser
US5208819A (en) * 1992-01-23 1993-05-04 General Instrument Corporation Optical source with frequency locked to an in-fiber grating resonantor
US5367589A (en) * 1993-10-22 1994-11-22 At&T Bell Laboratories Optical fiber package
US5380995A (en) * 1992-10-20 1995-01-10 Mcdonnell Douglas Corporation Fiber optic grating sensor systems for sensing environmental effects
US5384884A (en) * 1990-11-08 1995-01-24 British Telecommunications Public Limited Company Method of forming optical fibre gratings
US5392117A (en) * 1992-07-21 1995-02-21 Institut National D'optique Fabry-Perot optical sensing device for measuring a physical parameter
US5394415A (en) * 1992-12-03 1995-02-28 Energy Compression Research Corporation Method and apparatus for modulating optical energy using light activated semiconductor switches
US5397891A (en) * 1992-10-20 1995-03-14 Mcdonnell Douglas Corporation Sensor systems employing optical fiber gratings
US5401956A (en) * 1993-09-29 1995-03-28 United Technologies Corporation Diagnostic system for fiber grating sensors
US5430574A (en) * 1994-07-25 1995-07-04 Litton Systems, Inc. Rugged optical filter and switch for communication networks
US5469520A (en) * 1994-09-30 1995-11-21 United Technologies Corporation Compression-tuned fiber grating
US5557468A (en) * 1995-05-16 1996-09-17 Jds Fitel Inc Chromatic dispersion compensation device
US5591965A (en) * 1995-05-08 1997-01-07 Udd; Eric Multiparameter sensor system using a multiple grating fiber optic birefringent fiber
US5608562A (en) * 1994-05-25 1997-03-04 Lucent Technologies Inc. Optical communications system with adjustable dispersion compensation
US5612805A (en) * 1994-06-07 1997-03-18 Alcatel Cit Add-drop optical spectrum-division multiplexer
US5655040A (en) * 1994-12-15 1997-08-05 Alcatel N.V. Method of forming a dispersing grating in an optical fiber
US5673129A (en) * 1996-02-23 1997-09-30 Ciena Corporation WDM optical communication systems with wavelength stabilized optical selectors
US5680489A (en) * 1996-06-28 1997-10-21 The United States Of America As Represented By The Secretary Of The Navy Optical sensor system utilizing bragg grating sensors
US5680491A (en) * 1992-09-29 1997-10-21 Sumitomo Electric Industries, Ltd. Optical fiber dispersion compensation device for optical communication system
US5691989A (en) * 1991-07-26 1997-11-25 Accuwave Corporation Wavelength stabilized laser sources using feedback from volume holograms
US5691999A (en) * 1994-09-30 1997-11-25 United Technologies Corporation Compression-tuned fiber laser
US5694501A (en) * 1994-11-02 1997-12-02 Electrophotonics Corporation Apparatus and method of bragg intra-grating strain control
US5706301A (en) * 1995-08-16 1998-01-06 Telefonaktiebolaget L M Ericsson Laser wavelength control system
US5712717A (en) * 1995-03-03 1998-01-27 France Telecom High isolation, optical add-drop multiplexer
US5719971A (en) * 1995-01-09 1998-02-17 Optelecom, Inc. Strain based optical fiber systems
US5748349A (en) * 1996-03-27 1998-05-05 Ciena Corp. Gratings-based optical add-drop multiplexers for WDM optical communication system
US5751243A (en) * 1990-10-29 1998-05-12 Essex Corporation Image synthesis using time sequential holography
US5754321A (en) * 1996-10-15 1998-05-19 Lucent Technologies Inc. Add/drop optical circuit for a wavelength-division multiplexed network
US5771112A (en) * 1995-06-21 1998-06-23 France Telecom Reconfigurable device for insertion-extraction of wavelengths
US5778118A (en) * 1996-12-03 1998-07-07 Ciena Corporation Optical add-drop multiplexers for WDM optical communication systems
US5780843A (en) * 1996-07-16 1998-07-14 Universite Laval Absolute optical frequency calibrator for a variable frequency optical source
US5784191A (en) * 1995-06-26 1998-07-21 The United States Of America As Represented By The Secretary Of The Army Frequency agile filter and technique
US5793907A (en) * 1996-03-28 1998-08-11 The Regents Of The University Of California Method and apparatus for a wavelength selective true-time delay for an optically controlled device
US5805751A (en) * 1995-08-29 1998-09-08 Arroyo Optics, Inc. Wavelength selective optical couplers
US5818585A (en) * 1997-02-28 1998-10-06 The United States Of America As Represented By The Secretary Of The Navy Fiber Bragg grating interrogation system with adaptive calibration
US5825792A (en) * 1996-07-11 1998-10-20 Northern Telecom Limited Wavelength monitoring and control assembly for WDM optical transmission systems
US5838437A (en) * 1997-04-09 1998-11-17 Micron Optics, Inc. Reference system for optical devices including optical scanners and spectrum analyzers
US5889901A (en) * 1997-06-06 1999-03-30 University Technology Corporation Strain measuring apparatus/method having a sensor and a reference optical fiber grating
US5892582A (en) * 1996-10-18 1999-04-06 Micron Optics, Inc. Fabry Perot/fiber Bragg grating multi-wavelength reference
US5915052A (en) * 1997-06-30 1999-06-22 Uniphase Telecommunications Products, Inc. Loop status monitor for determining the amplitude of the signal components of a multi-wavelength optical beam
US5915051A (en) * 1997-01-21 1999-06-22 Massascusetts Institute Of Technology Wavelength-selective optical add/drop switch
US5953141A (en) * 1996-10-03 1999-09-14 International Business Machines Corporation Dynamic optical add-drop multiplexers and wavelength-routing networks with improved survivability and minimized spectral filtering
US5956355A (en) * 1991-04-29 1999-09-21 Massachusetts Institute Of Technology Method and apparatus for performing optical measurements using a rapidly frequency-tuned laser
US5963567A (en) * 1997-02-13 1999-10-05 Lucent Technologies, Inc. Multi-wavelength laser source
US5974206A (en) * 1997-12-19 1999-10-26 Northern Telecom Limited Dispersion compensation with low polarization mode dispersion
US5982963A (en) * 1997-12-15 1999-11-09 University Of Southern California Tunable nonlinearly chirped grating
US5982962A (en) * 1997-03-29 1999-11-09 Koops; Hans W. P. Fiber-integrated microlenses and optical fiber FBG couplers, spectrometers, and multiplexers comprised thereof
US5987200A (en) * 1997-10-27 1999-11-16 Lucent Technologies Inc. Device for tuning wavelength response of an optical fiber grating
US5987197A (en) * 1997-11-07 1999-11-16 Cidra Corporation Array topologies for implementing serial fiber Bragg grating interferometer arrays
US5991476A (en) * 1998-05-12 1999-11-23 Hewlett-Packard Company Pump directed optical switching element
US5991483A (en) * 1998-02-10 1999-11-23 Lucent Technologies Inc. Optical fiber grating packages
US5995255A (en) * 1997-10-28 1999-11-30 Lucent Technologies Inc. Concatenated fiber grating optical monitor
US5999671A (en) * 1997-10-27 1999-12-07 Lucent Technologies Inc. Tunable long-period optical grating device and optical systems employing same
US6008920A (en) * 1998-03-11 1999-12-28 Optical Coating Laboratory, Inc. Multiple channel multiplexer/demultiplexer devices
US6035080A (en) * 1997-06-20 2000-03-07 Henry; Charles Howard Reconfigurable add-drop multiplexer for optical communications systems
US6044189A (en) * 1996-12-03 2000-03-28 Micron Optics, Inc. Temperature compensated fiber Bragg gratings
US6055348A (en) * 1998-09-23 2000-04-25 Lucent Technologies Inc. Tunable grating device and optical communication devices and systems comprising same
US6055081A (en) * 1995-03-15 2000-04-25 Sumitomo Electric Industries, Ltd. Chromatic dispersion compensator and chromatic dispersion compensating optical communication system
US6069719A (en) * 1997-07-30 2000-05-30 Ciena Corporation Dynamically reconfigurable optical add-drop multiplexers for WDM optical communication systems
US6072567A (en) * 1997-02-12 2000-06-06 Cidra Corporation Vertical seismic profiling system having vertical seismic profiling optical signal processing equipment and fiber Bragg grafting optical sensors
US6088088A (en) * 1999-03-31 2000-07-11 Hewlett-Packard Company Chromatic dispersion measurement scheme having high frequency resolution
US6097487A (en) * 1997-02-14 2000-08-01 Optoplan As Device for measurement of optical wavelengths
US6104515A (en) * 1999-02-01 2000-08-15 Otera Corporation Method and apparatus for providing high-order polarization mode dispersion compensation using temporal imaging
US6111681A (en) * 1996-02-23 2000-08-29 Ciena Corporation WDM optical communication systems with wavelength-stabilized optical selectors
US6118530A (en) * 1999-05-18 2000-09-12 Bouevitch; Oleg Optical scanning spectrometer
US6122418A (en) * 1996-03-29 2000-09-19 British Telecommunications Chromatic dispersion compensating node
US6128427A (en) * 1998-08-28 2000-10-03 Lucent Technologies Inc. Articles and systems comprising digitally tunable optical gratings
US6134003A (en) * 1991-04-29 2000-10-17 Massachusetts Institute Of Technology Method and apparatus for performing optical measurements using a fiber optic imaging guidewire, catheter or endoscope
US6137924A (en) * 1998-09-02 2000-10-24 Lucent Technologies Inc. Article comprising a dispersion compensating grating with low polarization mode dispersion
US6141470A (en) * 1998-02-06 2000-10-31 Lucent Technologies, Inc. Magnetically reconfigurable optical grating devices and communication systems
US6148127A (en) * 1998-09-23 2000-11-14 Lucent Technologies Inc. Tunable dispersion compensator and optical system comprising same
US6154590A (en) * 1998-09-28 2000-11-28 Lucent Technologies Inc. Wavelength-tunable devices and systems comprising flexed optical gratings
US6154588A (en) * 1997-10-20 2000-11-28 Fujitsu Limited Dispersion compensation apparatus
US6157477A (en) * 1998-05-27 2000-12-05 Mci Communications Corporations Bidirectional dispersion compensation system
US6169829B1 (en) * 1995-02-22 2001-01-02 Pirelli Cavi E Sistemi S.P.A. Chirped optical fibre grating
US6169831B1 (en) * 1998-09-23 2001-01-02 Lucent Technologies Inc. Method of making optical chirped grating with an intrinsically chirped grating and external gradient
US6185023B1 (en) * 1996-03-27 2001-02-06 Ciena Corporation Optical add-drop multiplexers compatible with very dense WDM optical communication systems
US6188499B1 (en) * 1997-05-14 2001-02-13 Canon Kabushiki Kaisha Wavelength locking method for tunable filter, wavelength locking apparatus and wavelength division multiplexing communication network using the same
US6201909B1 (en) * 1996-10-25 2001-03-13 Arroyo Optics, Inc. Wavelength selective optical routers
US6229827B1 (en) * 1998-12-04 2001-05-08 Cidra Corporation Compression-tuned bragg grating and laser
US6240220B1 (en) * 1998-07-29 2001-05-29 E-Tek Dynamics, Inc. Tunable optical fiber package
US6278811B1 (en) * 1998-12-04 2001-08-21 Arthur D. Hay Fiber optic bragg grating pressure sensor

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO942357D0 (en) * 1994-06-20 1994-06-20 Geco As
GB9501672D0 (en) 1995-01-27 1995-03-15 Univ Southampton Dispersion compensation in optical fibre transmission

Patent Citations (88)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4589285A (en) * 1984-11-05 1986-05-20 Western Geophysical Co. Of America Wavelength-division-multiplexed receiver array for vertical seismic profiling
US5022730A (en) * 1989-12-12 1991-06-11 At&T Bell Laboratories Wavelength tunable optical filter
US5042898A (en) * 1989-12-26 1991-08-27 United Technologies Corporation Incorporated Bragg filter temperature compensated optical waveguide device
US5751243A (en) * 1990-10-29 1998-05-12 Essex Corporation Image synthesis using time sequential holography
US5384884A (en) * 1990-11-08 1995-01-24 British Telecommunications Public Limited Company Method of forming optical fibre gratings
US6134003A (en) * 1991-04-29 2000-10-17 Massachusetts Institute Of Technology Method and apparatus for performing optical measurements using a fiber optic imaging guidewire, catheter or endoscope
US5956355A (en) * 1991-04-29 1999-09-21 Massachusetts Institute Of Technology Method and apparatus for performing optical measurements using a rapidly frequency-tuned laser
US5159601A (en) * 1991-07-17 1992-10-27 General Instrument Corporation Method for producing a tunable erbium fiber laser
US5691989A (en) * 1991-07-26 1997-11-25 Accuwave Corporation Wavelength stabilized laser sources using feedback from volume holograms
US5208819A (en) * 1992-01-23 1993-05-04 General Instrument Corporation Optical source with frequency locked to an in-fiber grating resonantor
US5392117A (en) * 1992-07-21 1995-02-21 Institut National D'optique Fabry-Perot optical sensing device for measuring a physical parameter
US5680491A (en) * 1992-09-29 1997-10-21 Sumitomo Electric Industries, Ltd. Optical fiber dispersion compensation device for optical communication system
US5380995A (en) * 1992-10-20 1995-01-10 Mcdonnell Douglas Corporation Fiber optic grating sensor systems for sensing environmental effects
US5397891A (en) * 1992-10-20 1995-03-14 Mcdonnell Douglas Corporation Sensor systems employing optical fiber gratings
US5394415A (en) * 1992-12-03 1995-02-28 Energy Compression Research Corporation Method and apparatus for modulating optical energy using light activated semiconductor switches
US5401956A (en) * 1993-09-29 1995-03-28 United Technologies Corporation Diagnostic system for fiber grating sensors
US5367589A (en) * 1993-10-22 1994-11-22 At&T Bell Laboratories Optical fiber package
US5608562A (en) * 1994-05-25 1997-03-04 Lucent Technologies Inc. Optical communications system with adjustable dispersion compensation
US5612805A (en) * 1994-06-07 1997-03-18 Alcatel Cit Add-drop optical spectrum-division multiplexer
US5430574A (en) * 1994-07-25 1995-07-04 Litton Systems, Inc. Rugged optical filter and switch for communication networks
US5469520A (en) * 1994-09-30 1995-11-21 United Technologies Corporation Compression-tuned fiber grating
US5691999A (en) * 1994-09-30 1997-11-25 United Technologies Corporation Compression-tuned fiber laser
US5694501A (en) * 1994-11-02 1997-12-02 Electrophotonics Corporation Apparatus and method of bragg intra-grating strain control
US5655040A (en) * 1994-12-15 1997-08-05 Alcatel N.V. Method of forming a dispersing grating in an optical fiber
US5719971A (en) * 1995-01-09 1998-02-17 Optelecom, Inc. Strain based optical fiber systems
US6169829B1 (en) * 1995-02-22 2001-01-02 Pirelli Cavi E Sistemi S.P.A. Chirped optical fibre grating
US5712717A (en) * 1995-03-03 1998-01-27 France Telecom High isolation, optical add-drop multiplexer
US6055081A (en) * 1995-03-15 2000-04-25 Sumitomo Electric Industries, Ltd. Chromatic dispersion compensator and chromatic dispersion compensating optical communication system
US5591965A (en) * 1995-05-08 1997-01-07 Udd; Eric Multiparameter sensor system using a multiple grating fiber optic birefringent fiber
US5557468A (en) * 1995-05-16 1996-09-17 Jds Fitel Inc Chromatic dispersion compensation device
US5771112A (en) * 1995-06-21 1998-06-23 France Telecom Reconfigurable device for insertion-extraction of wavelengths
US5784191A (en) * 1995-06-26 1998-07-21 The United States Of America As Represented By The Secretary Of The Army Frequency agile filter and technique
US5706301A (en) * 1995-08-16 1998-01-06 Telefonaktiebolaget L M Ericsson Laser wavelength control system
US5805751A (en) * 1995-08-29 1998-09-08 Arroyo Optics, Inc. Wavelength selective optical couplers
US6249365B1 (en) * 1996-02-23 2001-06-19 Ciena Corporation WDM optical communication systems with wavelength-stabilized optical selectors
US6111681A (en) * 1996-02-23 2000-08-29 Ciena Corporation WDM optical communication systems with wavelength-stabilized optical selectors
US5673129A (en) * 1996-02-23 1997-09-30 Ciena Corporation WDM optical communication systems with wavelength stabilized optical selectors
US6185023B1 (en) * 1996-03-27 2001-02-06 Ciena Corporation Optical add-drop multiplexers compatible with very dense WDM optical communication systems
US5748349A (en) * 1996-03-27 1998-05-05 Ciena Corp. Gratings-based optical add-drop multiplexers for WDM optical communication system
US5793907A (en) * 1996-03-28 1998-08-11 The Regents Of The University Of California Method and apparatus for a wavelength selective true-time delay for an optically controlled device
US6122418A (en) * 1996-03-29 2000-09-19 British Telecommunications Chromatic dispersion compensating node
US5680489A (en) * 1996-06-28 1997-10-21 The United States Of America As Represented By The Secretary Of The Navy Optical sensor system utilizing bragg grating sensors
US5825792A (en) * 1996-07-11 1998-10-20 Northern Telecom Limited Wavelength monitoring and control assembly for WDM optical transmission systems
US5780843A (en) * 1996-07-16 1998-07-14 Universite Laval Absolute optical frequency calibrator for a variable frequency optical source
US5953141A (en) * 1996-10-03 1999-09-14 International Business Machines Corporation Dynamic optical add-drop multiplexers and wavelength-routing networks with improved survivability and minimized spectral filtering
US6208443B1 (en) * 1996-10-03 2001-03-27 International Business Machines Corporation Dynamic optical add-drop multiplexers and wavelength-routing networks with improved survivability and minimized spectral filtering
US5754321A (en) * 1996-10-15 1998-05-19 Lucent Technologies Inc. Add/drop optical circuit for a wavelength-division multiplexed network
US5892582A (en) * 1996-10-18 1999-04-06 Micron Optics, Inc. Fabry Perot/fiber Bragg grating multi-wavelength reference
US6115122A (en) * 1996-10-18 2000-09-05 Micron Optics, Inc. Fabry-perot fiber bragg grating multi-wavelength reference
US6201909B1 (en) * 1996-10-25 2001-03-13 Arroyo Optics, Inc. Wavelength selective optical routers
US6044189A (en) * 1996-12-03 2000-03-28 Micron Optics, Inc. Temperature compensated fiber Bragg gratings
US5778118A (en) * 1996-12-03 1998-07-07 Ciena Corporation Optical add-drop multiplexers for WDM optical communication systems
US5915051A (en) * 1997-01-21 1999-06-22 Massascusetts Institute Of Technology Wavelength-selective optical add/drop switch
US6072567A (en) * 1997-02-12 2000-06-06 Cidra Corporation Vertical seismic profiling system having vertical seismic profiling optical signal processing equipment and fiber Bragg grafting optical sensors
US5963567A (en) * 1997-02-13 1999-10-05 Lucent Technologies, Inc. Multi-wavelength laser source
US6097487A (en) * 1997-02-14 2000-08-01 Optoplan As Device for measurement of optical wavelengths
US5818585A (en) * 1997-02-28 1998-10-06 The United States Of America As Represented By The Secretary Of The Navy Fiber Bragg grating interrogation system with adaptive calibration
US5982962A (en) * 1997-03-29 1999-11-09 Koops; Hans W. P. Fiber-integrated microlenses and optical fiber FBG couplers, spectrometers, and multiplexers comprised thereof
US5838437A (en) * 1997-04-09 1998-11-17 Micron Optics, Inc. Reference system for optical devices including optical scanners and spectrum analyzers
US6188499B1 (en) * 1997-05-14 2001-02-13 Canon Kabushiki Kaisha Wavelength locking method for tunable filter, wavelength locking apparatus and wavelength division multiplexing communication network using the same
US5889901A (en) * 1997-06-06 1999-03-30 University Technology Corporation Strain measuring apparatus/method having a sensor and a reference optical fiber grating
US6035080A (en) * 1997-06-20 2000-03-07 Henry; Charles Howard Reconfigurable add-drop multiplexer for optical communications systems
US5915052A (en) * 1997-06-30 1999-06-22 Uniphase Telecommunications Products, Inc. Loop status monitor for determining the amplitude of the signal components of a multi-wavelength optical beam
US6069719A (en) * 1997-07-30 2000-05-30 Ciena Corporation Dynamically reconfigurable optical add-drop multiplexers for WDM optical communication systems
US6154588A (en) * 1997-10-20 2000-11-28 Fujitsu Limited Dispersion compensation apparatus
US5987200A (en) * 1997-10-27 1999-11-16 Lucent Technologies Inc. Device for tuning wavelength response of an optical fiber grating
US5999671A (en) * 1997-10-27 1999-12-07 Lucent Technologies Inc. Tunable long-period optical grating device and optical systems employing same
US5995255A (en) * 1997-10-28 1999-11-30 Lucent Technologies Inc. Concatenated fiber grating optical monitor
US5987197A (en) * 1997-11-07 1999-11-16 Cidra Corporation Array topologies for implementing serial fiber Bragg grating interferometer arrays
US5982963A (en) * 1997-12-15 1999-11-09 University Of Southern California Tunable nonlinearly chirped grating
US5974206A (en) * 1997-12-19 1999-10-26 Northern Telecom Limited Dispersion compensation with low polarization mode dispersion
US6141470A (en) * 1998-02-06 2000-10-31 Lucent Technologies, Inc. Magnetically reconfigurable optical grating devices and communication systems
US5991483A (en) * 1998-02-10 1999-11-23 Lucent Technologies Inc. Optical fiber grating packages
US6008920A (en) * 1998-03-11 1999-12-28 Optical Coating Laboratory, Inc. Multiple channel multiplexer/demultiplexer devices
US5991476A (en) * 1998-05-12 1999-11-23 Hewlett-Packard Company Pump directed optical switching element
US6157477A (en) * 1998-05-27 2000-12-05 Mci Communications Corporations Bidirectional dispersion compensation system
US6240220B1 (en) * 1998-07-29 2001-05-29 E-Tek Dynamics, Inc. Tunable optical fiber package
US6128427A (en) * 1998-08-28 2000-10-03 Lucent Technologies Inc. Articles and systems comprising digitally tunable optical gratings
US6137924A (en) * 1998-09-02 2000-10-24 Lucent Technologies Inc. Article comprising a dispersion compensating grating with low polarization mode dispersion
US6148127A (en) * 1998-09-23 2000-11-14 Lucent Technologies Inc. Tunable dispersion compensator and optical system comprising same
US6169831B1 (en) * 1998-09-23 2001-01-02 Lucent Technologies Inc. Method of making optical chirped grating with an intrinsically chirped grating and external gradient
US6055348A (en) * 1998-09-23 2000-04-25 Lucent Technologies Inc. Tunable grating device and optical communication devices and systems comprising same
US6154590A (en) * 1998-09-28 2000-11-28 Lucent Technologies Inc. Wavelength-tunable devices and systems comprising flexed optical gratings
US6229827B1 (en) * 1998-12-04 2001-05-08 Cidra Corporation Compression-tuned bragg grating and laser
US6278811B1 (en) * 1998-12-04 2001-08-21 Arthur D. Hay Fiber optic bragg grating pressure sensor
US6104515A (en) * 1999-02-01 2000-08-15 Otera Corporation Method and apparatus for providing high-order polarization mode dispersion compensation using temporal imaging
US6088088A (en) * 1999-03-31 2000-07-11 Hewlett-Packard Company Chromatic dispersion measurement scheme having high frequency resolution
US6118530A (en) * 1999-05-18 2000-09-12 Bouevitch; Oleg Optical scanning spectrometer

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060127004A1 (en) * 2004-12-13 2006-06-15 General Dynamics Advanced Information Systems, Inc. System and method for performing dispersion compensation
US7295738B2 (en) * 2004-12-13 2007-11-13 General Dynamics Advanced Information Systems, Inc. System and method for performing dispersion compensation
US20180069635A1 (en) * 2016-09-02 2018-03-08 Adva Optical Networking Se Method and Optical Transmitter Device for Creating an Optical Binary Digital Transmit Signal
US10355784B2 (en) * 2016-09-02 2019-07-16 Adva Optical Networking Se Method and optical transmitter device for creating an optical binary digital transmit signal

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