Gerald W Mitchell

US Patent:

20050058165, Mar 17, 2005

Filed:

Sep 12, 2003

Appl. No.:

10/661435

Inventors:

James Morehead - Oakland CA, US
Mark Arbore - Los Altos CA, US
Gerald Mitchell - Los Altos CA, US

Assignee:

Lightwave Electronics Corporation - Mountain View CA

International Classification:

H01S003/14

US Classification:

372039000, 372070000

Abstract:

The use of -oriented crystals as gain media in lasers and optical amplifiers is disclosed. In a laser, a substantially -oriented crystal, such as YAG can be disposed within an optical cavity as a gain medium. The crystal is orientated such that a plane is substantially perpendicular to a direction of beam propagation within the crystal. A pump source provides pumping energy to a pumped region of the crystal. The use of a substantially -oriented crystal can reduce depolarization loss and thermal lens effects if an absorbed power of the pumping energy is less than or equal to about 1000 watts of pumping radiation and/or a cross-sectional overlap between a beam of radiation propagating through the crystal and the pumped region is greater than about 20% of a cross-sectional area of the pumped region.

US Patent:

48624691, Aug 29, 1989

Filed:

Oct 10, 1986

Appl. No.:

6/917721

Inventors:

Bernard Couillaud - Palo Alto CA
Gerald M. Mitchell - Cupertino CA

Assignee:

Coherent, Inc. - Palo Alto CA

International Classification:

H01S 310

US Classification:

372 33

Abstract:

The subject invention relates to method of suppressing one of the counterpropagating intracavity pulses generated in a dye laser synchronously pumped by the output of a mode locked Q-switched pump laser. The method includes extracting a portion of one of the pulses generated in the cavity such that the other pulse experiences a greater effective gain. The pulse with the highest effective gain will dominate the other pulse and at the steady state only one pulse will exist in the cavity. In the preferred embodiment, a double pass acousto-optic cell is used to extract the both the unwanted pulse and, at a later time, the high energy, useful pulse. In this case, maximum efficiency is achieved by placing the dye cell at one of a number of well defined locations within the optical cavity.

US Patent:

52579891, Nov 2, 1993

Filed:

Jan 13, 1992

Appl. No.:

7/820303

Inventors:

Enrique M. Celaya - San Francisco CA
Gerald M. Mitchell - Cupertino CA
Richard G. Caro - Palo Alto CA
Nubar Manoukian - Cupertino CA

Assignee:

Coherent, Inc. - Palo Alto CA

International Classification:

A61N 506

US Classification:

606 6

Abstract:

A method and apparatus for minimizing damage to an optical fiber used as part of a laser radiation delivery system are disclosed. The apparatus includes the use of a spacer positioned adjacent the tip of the fiber to minimize the impact on the fiber tip of debris and vapor generated by exposure of a tissue target to high energy radiation. The end of the apparatus is configured to vent debris and vapor from the end of the tip to reduce damage. The fiber tip may also be annealed to enhance its resistance to damage. The method includes the step of spacing the fiber tip at a predetermined distance from the tissue target during exposure of the tissue target to laser radiation, and may include venting the debris created away from the fiber end. The method may further include the step of providing an annealed fiber tip.