Gerald F Barker

US Patent:

51249987, Jun 23, 1992

Filed:

May 21, 1990

Appl. No.:

7/525907

Inventors:

Marco Arrigoni - Sunnyvale CA
Gerald C. Barker - Palo Alto CA
William Kolb - Redwood City CA
Benjamin Cook - Livermore CA
Joseph Fraizer - Mountain View CA

Assignee:

Coherent, Inc. - Palo Alto CA

International Classification:

H01S 303

US Classification:

372 61

Abstract:

A sealed laser plasma tube for use in a gas laser system. A Brewster window seals one end of the tube (the cathode end, in a preferred embodiment), and an end mirror which seals the opposite tube end (the anode end, in a preferred embodiment). In a laser system embodying the invention, a second end mirror is positioned adjacent to, but spaced from, the Brewster window. Intra-cavity elements may conveniently be inserted and replaced in the region between the sealed Brewster window and the second end mirror. The sealed mirror which seals the tube end opposite the window is preferably coated with at least an outermost layer of Hafnium oxide, to protect it from hard UV radiation originating within the plasma tube. The inventors have recognized that the problem of sealed window degradation is substantially less severe at the cathode end of an ion laser plasma tube, and that the sealed window should be attached at the tube end at which the window degradation problem is less severe.

US Patent:

40191540, Apr 19, 1977

Filed:

Oct 31, 1975

Appl. No.:

5/627714

Inventors:

Gerald C. Barker - Palo Alto CA

Assignee:

Coherent Radiation - Palo Alto CA

International Classification:

H01S 302

US Classification:

331 945T

Abstract:

In order to prevent electrical discharges between the cathode electrode of a gas discharge laser and the closest metal resonator mirror, means are provided adjacent the optical path between the closest resonator mirror and the cathode electrode for conveying the electrical discharge from the cathode electrode to a reflectively inactive area of the mirror. In one preferred embodiment the electrically conducting means is a flanged tube coaxial with the optical path and having the flanged portion in electrical contact with the reflectively inactive area. In other embodiments the electrical conducting means include a metal block having a bore which is coaxial with the optical path; the block being in electrical contact with a reflectively inactive area of the mirror. In still another embodiment the electrical conducting means include a rod projecting from the mirror mounting block which is electrically connected to a reflectively inactive area of the mirror.

US Patent:

47363797, Apr 5, 1988

Filed:

Dec 6, 1985

Appl. No.:

6/806040

Inventors:

Gerald C. Barker - Palo Alto CA
Jeffrey L. Cannon - San Jose CA
Richard D. Cullins - Cupertino CA

Assignee:

Coherent, Inc. - Palo Alto CA

International Classification:

H01S 304

US Classification:

372 34

Abstract:

The subject invention relates to a conduction cooled ion laser capable of producing higher output power. The device includes an insulated tube and a plurality of heat conducting members mounted in thermal contact with the wall of the tube. Primary and secondary ring gas barriers or shields project axially from the heat conducting members with the primary shield being located radially inward with respect to the secondary shield. The shields are mounted such that they axially overlap to define a reentrant configuration. The reentrant configuration allows for the operation of the laser at a higher power with the same voltage safety margin above the instability voltage.

US Patent:

40619869, Dec 6, 1977

Filed:

Jan 2, 1976

Appl. No.:

5/646330

Inventors:

Gerald C. Barker - Palo Alto CA

Assignee:

Coherent Radiation - Palo Alto CA

International Classification:

H01S 309
H01S 3097

US Classification:

331 945PE

Abstract:

A pulsed power supply for a gas discharge laser in which a main DC power supply is connected in series with a current limited DC power supply and a gas discharge laser and with diode means connected across the second power supply for bypassing the second power supply and conducting current from the main power supply to the laser after the laser ionizes.

US Patent:

46721681, Jun 9, 1987

Filed:

Oct 25, 1978

Appl. No.:

5/954404

Inventors:

Richard J. Saunders - San Jose CA
Derek L. Hine - Menlo Park CA
Gerald C. Barker - Palo Alto CA

Assignee:

Coherent, Inc. - Palo Alto CA

International Classification:

B23K 2600

US Classification:

219121LK

Abstract:

Apparatus is disclosed for forming plural rows of holes in a web of sheet material being advanced longitudinally along a unidirectional path of travel, the apparatus including a continuous wave laser and beam delivery apparatus. Beam delivering means delivers substantially the entire energy of the laser beam for predetermined periods of time to discrete web portions spaced apart across the web and includes means periodically interposed into and removed from the path of the laser beam for deflecting the beam periodically toward the web portions.