High power waveguide laser

• US 6,788,722 B1
• Filed: 07/10/2000
• Issued: 09/07/2004
• Est. Priority Date: 07/10/2000
• Status: Expired due to Fees

• Current Assignee: Coherent Inc (Coherent Corp.)
• Original Assignee: Coherent Inc (Coherent Corp.)
• Inventors: Kennedy, John T., DeMaria, Anthony J., Newman, Leon A., Hart, Richard A.
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Jackson, Cornelius H.
• Application Number:
  US09/612,733
• Time in Patent Office: 1,520 Days
• Field of Search: 372/55, 372/61, 372/64, 372/81, 372/87, 372/95
• US Class Current: 372/64
• CPC Class Codes: H01S 3/03 of gas laser discharge tubes
• CPC Class Codes: H01S 3/0315 Waveguide lasers
• CPC Class Codes: H01S 3/038 Electrodes, e.g. special shape, configuration or composition
• CPC Class Codes: H01S 3/076 Folded-path lasers
• CPC Class Codes: H01S 3/09702 Details of the driver electronics and electric discharge circuits
• CPC Class Codes: H01S 3/09705 with particular means for stabilising the discharge

Abstract

The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by a laser of the present invention. In accordance with the present invention the laser comprises a housing defining a plurality of compartments therein, a folded waveguide disposed within the housing, the folded waveguide defining a plurality of channels having a substantially rectangular cross section for guiding a laser beam, a plurality of electrodes disposed in the plurality of compartments and juxtaposed along opposite surfaces of the waveguide and at least one power supply connected to the plurality of electrodes. The channels having a prescribed width to height ratio for a prescribed channel length for a given Fresnel number. At least one optical housing is provided. The optical housing is mounted to the laser housing, the optical housing including a plurality of beam turning mechanisms disposed within a plurality of compartments accessible for adjusting the beam turning mechanisms. The channels are disposed within the waveguide so as to subtend a prescribed angular orientation between adjacent channels. Inductors are provided for suppressing the capacitance of the electrodes.

Claims

1. A laser structure comprising:

an elongated, dielectric waveguide structure having a plurality of waveguide channels therein, said waveguide channels including a gaseous gain medium;

a pair of electrodes including a first electrode extending along a first elongated surface of the waveguide structure and a second electrode extending along a second elongated surface of the waveguide structure, the first elongated surface being opposite and parallel to the second elongated surface, each of said first and second electrodes being divided into spaced apart first and second electrode portions, each of said spaced apart first and second electrode portions of said first electrode being electrically connectable to an RF power supply for applying an RF potential across said gain medium;

a metal housing enclosing said waveguide structure and said pair of electrodes, with said first electrode being electrically isolated from said metal housing; and

a metal shield located between said spaced apart first and second portions of each of said first and second electrodes, the metal shield being positioned orthogonal to said first and second elongated surfaces so as to prevent RF coupling between said spaced apart first and second portions.

2. The laser structure of claim 1 wherein said spaced apart first and second portions of said second electrode are electrically connected to said metal housing.

3. A laser structure comprising:

a laser resonator having a resonator axis;

an elongated dielectric waveguide structure having a plurality of waveguide channels therein, said waveguide channels including a gaseous gain medium, and said resonator axis extending through said plurality of waveguide channels;

a pair of electrodes including a first electrode extending along a first elongated surface of the waveguide structure and a second electrode extending along a second elongated surface of the waveguide structure, the first elongated surface being opposite and parallel to the second elongated surface, each of said first and second electrodes being divided into spaced apart first and second electrode portions, each of said spaced apart first and second electrode portions of said first electrode being electrically connectable to an RF power supply for applying RF energy to said gain medium, thereby causing laser radiation to circulate in said laser resonator as guided by said waveguide channels;

a metal housing enclosing said waveguide structure and said pair of electrodes, with said first electrode being electrically isolated from said metal housing; and

a metal shield located between spaced apart first and second portions of each of said first and second electrodes transverse to said waveguide structure to prevent RF coupling between said spaced apart first and second portions, said metal shield being electrically isolated from said first electrode and electrically connected to said metal housing.

4. The laser structure of claim 3, wherein said metal housing is grounded.

5. The laser structure of claim 3 wherein said spaced apart first and second portions of said second electrode are each electrically connected to said metal housing.

6. The laser structure of claim 3, wherein said metal shield is in the form of an elongated metal plate having a plurality of spaced-apart metal fingers extending therefrom, with spaces between said metal fingers arranged to allow passage therethrough of laser radiation guided by said waveguide channels.

7. The laser structure of claim 6, wherein said metal fingers extend through holes in said waveguide structure.

8. The laser structure of claim 7, wherein said shield is located at a predetermined distance from said spaced apart first and second portions of said first and second electrodes, said predetermined distance being selected to prevent electrical arcing between said spaced apart first and second portions of said first and second electrodes.

9. A laser comprising:

a laser resonator having a resonator axis;

an elongated dielectric waveguide structure having a plurality of waveguide channels therein, said waveguide channels including a gaseous gain medium, and said resonator axis extending through said plurality of waveguide channels;

an RF power supply;

a pair of electrodes including a first electrode extending along a first elongated surface of the waveguide structure and a second electrode extending along a second elongated surface of the waveguide structure, the first elongated surface being opposite and parallel to the second elongated surface, each of said first and second electrodes being divided into spaced apart first and second electrode portions, each of said spaced apart first and second electrode portions of said first electrode being electrically connected to said RF power supply for applying RF energy to said gain medium, thereby causing laser radiation to circulate in said laser resonator guided by said waveguide channels;

a metal housing enclosing said waveguide structure and said first and second electrodes, with said first electrode being electrically isolated from said metal housing; and

a metal shield located between spaced apart first and second portions of each of said first and second electrodes transverse to said waveguide structure to prevent RF coupling between said spaced apart first and second portions, said metal shield being electrically isolated from said first electrode and electrically connected to said metal housing.

10. The laser of claim 9, wherein said metal shield is in the form of an elongated metal plate having a plurality of spaced-apart metal fingers extending therefrom, with spaces between said metal fingers arranged to allow passage of laser radiation guided by said waveguide channels.

11. A laser comprising:

a laser resonator having a resonator axis;

an elongated dielectric waveguide structure having a plurality of waveguide channels therein, said waveguide channels including a gaseous gain medium, and said resonator axis extending through said plurality of waveguide channels;

a pair of electrodes including a first electrode extending along a first elongated surface of the waveguide structure and a second electrode extending along a second elongated surface of the waveguide structure, the first elongated surface being opposite and parallel to the second elongated surface, each of said first and second electrodes being divided into spaced apart first and second electrode portions;

a metal housing enclosing said waveguide structure and said pair of electrodes, with said first and second electrode portions of said first electrode being electrically isolated from said metal housing, and said first and second electrode portions of said second electrode being electrically connected to said metal housing;

first and second RF power supplies, said first portion of said first electrode being electrically connected to said first RF power supply, and said second portion of said first electrode being electrically connected to said second RF power supply for applying RF energy to said gain medium, thereby causing laser radiation to circulate in said laser resonator guided by said waveguide channels; and

a metal shield located between spaced apart first and second portions of each of said first and second electrodes transverse to said waveguide structure to prevent RF coupling between said spaced apart first and second portions, said metal shield being electrically isolated from said first electrode and electrically connected to said metal housing.

12. The laser of claim 11, wherein said metal shield is in the form of an elongated metal plate having a plurality of spaced-apart metal fingers extending therefrom, with spaces between said metal fingers arranged to allow passage of laser radiation guided by said waveguide channels.

13. The laser of claim 11, wherein said first and second RF power supplies share a common oscillator and at least one preamplifier, whereby each of the first and second electrodes can be driven in phase.