High frequency RF discharge laser

• US 4,631,732 A
• Filed: 04/25/1984
• Issued: 12/23/1986
• Est. Priority Date: 04/25/1984
• Status: Expired due to Term

• Current Assignee: Clad P. Christensen
• Original Assignee: Clad P. Christensen
• Inventors: Christensen, Clad P.
• Primary Examiner(s): Scott, Jr., Leon
• Application Number:
  US06/603,846
• Time in Patent Office: 972 Days
• Field of Search: 372/82, 372/83, 372/86, 372/87, 333/248, 333/246
• US Class Current: 372/87
• CPC Class Codes: H01S 3/0315 Waveguide lasers
• CPC Class Codes: H01S 3/09713 with auxiliary ionisation, e.g. double discharge excitation
• CPC Class Codes: H01S 3/0975 using inductive or capacitive excitation

Abstract

A high frequency, high energy RF powered laser is shown and described. This laser utilizes a stripline wave guide electrode, a ground plane, and dielectric materials for the lasing tube to provide for resistance to spurious discharge and parasitic breakdown between the stripline and the ground plane. The use of a high voltage pulse to initiate lasing gas breakdown, the use of a dielectric section in the stripline wave guide to protect the RF source and a choke to protect the high voltage pulse source from RF energy are also shown and described.

Claims

1. A high frequency high power stabilized RF discharge laser comprising in combination;

a ground plane;

a stripline waveguide electrode having first and second ends located in a plane substantially parallel to said ground plane;

an RF souce connected to said first end of said stripline waveguide electrode by a means for preventing a high voltage pulse from damaging said RF source;

a discharge tube located between said ground plane and said stripline waveguide electrode;

preionization pulse means including a high voltage source applying a high voltage pulse to said second end of said stripline waveguide electrode and a means placed between said high voltage pulse source and said stripline waveguide electrode for preventing said RF from damaging said high voltage source; and

a waveguide region formed by said ground plane and said stripline waveguide electrode wherein said discharge tube lies within said waveguide region.

2. The apparatus of claim 1 wherein said preionization pulse means preionizes said gas.

3. The apparatus in accordance with claim 2 further including a dielectric section of material located in said stripline waveguide for preventing said preionization pulse from damaging the source of high power RF.

4. The apparatus in accordance with claim 1, further including dielectric insulation material located in said waveguide region.

5. The apparatus in accordance with claim 4, wherein said dielectric insulation material withstands high RF intensities without parasitic breakdown.

6. The apparatus in accordance with claim 5, wherein said dielectric insulation material is an inert material.

7. The apparatus in accordance with claim 1, wherein said discharge tube is constructed of a dielectric material.

8. The apparatus in accordance with claim 7, wherein said dielectric material is a ceramic material which resists corrosion by lasing gases.

9. The apparatus in accordance with claim 1, wherein a dielectric material covers the entire region defined by said ground plane, and extends under and beyond said stripline waveguide conductor.

10. The apparatus in accordance with claim 1, wherein the gas located in said discharge tube is under pressure in excess of one atmosphere.

11. The apparatus in accordance with claim 1, wherein the gas pressure in said discharge tube is greater than one atmosphere and as high as 10 atmospheres.

12. The apparatus in accordance wtih claim 1, wherein said RF frequency is greater than 900 MHz.

13. The apparatus in accordance with claim 1, wherein said discharge tube has a power level on the order of or greater than 10 kilowatts per centimeter cubed.

14. The apparatus in accordance with claim 1, wherein said gas is a carbon dioxide lasing gas.

15. The apparatus in accordance with claim 1, wherein said dielectric material provides a capacitive ballasting of the discharge which results in improved stability and homogeneity.

16. The apparatus in accordance with claim 1, wherein said gas is a high pressure gas selected from the group of carbon dioxide, rare gas halide XeF, XeCl, KrF, and ArF, neutral xenon and xenon dimer.

17. The apparatus of claim 1, wherein said gas is contained within a metal-free environment.

18. The apparatus of claim 1, further including a transmission line termination for said waveguide which provides for power transfer to the gas and reflection of RF power back into the RF source.

19. A high frequency high power stabilized discharge laser comprising an RF discharge laser having:

a stripline waveguide inducing a free ionization discharge into a discharge region by a means for applying a high voltage pulse to one end of said stripline electrode and a means for applying RF excitation to a second end of said stripline electrode; and

said discharge region having layers comprising in order;

conductor, dielectric, plasma, dielectric, and ground plane.

20. The apparatus in accordance with claim 19, wherein the stripline waveguide and ground plane are immersed in a dielectric which inhibits spurious discharges external to said discharge region.

21. The apparatus in accordance with claim 19, wherein said plasma lies in a region defined by two planar dielectric sheets which lie between said conductor and said ground plane.

22. Teh apparatus of claim 21, wherein said dielectric material is a fluid.

23. The apparatus of claims 21, wherein said dielectric material is a solid.

24. The apparatus in accordance with claim 19, wherein there is transverse flow of a lasing gas through the discharge region.

25. The apparatus of claim 19, wherein said discharge region includes a tube having a rectilinear cross section and is constructed with a dielectric material.

26. The apparatus of claim 24, wherein said gas is carbondioxide.