Pulsed laser system

United States Patent m

McDonald

[li] Patent Number: 4,601,037 [45] Date of Patent: Jul. 15, 1986

[54] PULSED LASER SYSTEM

[75] Inventor: John J. McDonald, San Marino, Calif.

[73] Assignee: Britt Corporation, Los Angeles, Calif.

[21] Appl. No.: 620,345

[22] Filed: Jun. 13,1984

[51] Int. CI.4 HOIS 3/10

[52] U.S. Q 372/25; 372/38;

372/30

[58] Field of Search 372/25, 26, 29, 8, 30,

372/32, 38, 69

[56] References Cited

U.S. PATENT DOCUMENTS

3,481,340 6/1965 McKnight et al. .

3,727,061 4/1973 Dworkin 372/8

3,747,019 7/1973 Koechner et al 372/30

3,928,815 12/1975 Hellwarth .

3,971,382 7/1976 Krasnov .

4,009,385 2/1977 Sell 372/29

4,053,845 10/1977 Gould .

4,161,436 7/1979 Gould .

4,243,951 1/1981 Wolkstein et al 372/26

4,359,773 11/1982 Swartzetal 372/29

4,409,979 10/1983 Roussel et al. .

4,412,331 10/1983 Chapman 372/29

Primary Examiner—Leon Scott, Jr.

Attorney, Agent, or Firm—Lawrence S. Levinson;

Robert E. Lee, Jr.

[57] ABSTRACT

A pulsed laser system capable of operating in a plurality of modes for delivering a burst of laser pulses to a target wherein the pulse width of the laser pulses are automatically controlled in response to the mode selected. A special calibration procedure allows the system to determine the pulse width and pulse repetition rate when the laser is producing a predetermined power output level as measured by a power meter at the target site. Using calibrated pulse width and pulse repetition rate, the pulse width and pulse repetition rate of the laser pulses to be delivered to the target for any particular treatment burst can be determined. Means are provided for determining the energy delivered to the target for any particular treatment burst. A potentiometer coupled to a laser spot size control lense assembly provides a signal proportional to the spot size. From this signal and the energy delivered, the energy density can be calculated. A special REPEAT mode allows the operator to repeat automatically at preselected intervals the firing of bursts of laser pulses characterized by repetition rate, pulse width and exposure time. The bursts will be repeated for as long as the foot pedal is depressed.

3 Claims, 10 Drawing Figures