LASER RESONATOR WITH PARASITIC MODE SUPPRESSION

1 . A resonator for a laser comprising:

a first resonator wall;

a second resonator wall that is separated from the first resonator wall in a transverse direction thereby defining a gap between the first and second resonator walls;

a lasing medium disposed in the gap;

a first mirror disposed at a first end of the first and second resonator walls;

a second mirror disposed at a second end of the first and second resonator walls,

wherein the mirrors cooperate to form an intra-cavity laser beam that travels along a plurality of paths through the lasing medium,

wherein the plurality of paths define a boundary of a superfluous region within the resonator, wherein the intra-cavity laser beam does not pass through the superfluous region;

wherein the first mirror and the second mirror fowl a laser resonator for a parasitic laser mode, a portion of which is located within the superfluous region; and

a parasitic mode suppressor that is located within the superfluous region.

2 . The resonator of claim 1 , wherein the parasitic mode suppressor is a recessed area on at least one of the first resonator and the second resonator wall.

3 . The resonator of claim 1 , wherein the parasitic mode suppressor is a protrusion on at least one of the first resonator and the second resonator wall.

4 . The resonator of claim 1 , wherein the parasitic mode suppressor is a spacer and the spacer is disposed in the gap.

5 . The resonator of claim 1 , wherein the parasitic mode suppressor is a spacer and the spacer is at least partially disposed in a recessed area formed within at least one of the first resonator wall and the second resonator wall.

6 . The resonator of claim 1 , wherein the parasitic mode suppressor is formed from one selected from a group consisting of a metal material and a ceramic material.

7 . The resonator of claim 1 , wherein the gap in a region adjacent to an upper surface of parasitic mode suppressor is less than or equal to about 0.3 mm.

8 . The resonator as claimed in claim 1 , wherein the lasing medium is a gas plasma discharge medium and the parasitic mode suppressor reduces a gas discharge in the superfluous region.

9 . The resonator of claim 1 , wherein the lasing medium is a solid state lasing medium and the parasitic mode suppressor is structure that is embedded in the solid state lasing medium.

10 . The resonator as claimed in claim 1 , wherein the lasing medium is a gas plasma discharge and the gas plasma discharge in a region between the first or second resonator wall and a surface of the parasitic mode suppressor is reduced relative to another region of the gain medium and the reduction is due to the presence of the parasitic mode suppressor.

11 . The resonator as claimed in claim 1 , wherein the lasing medium is a gas plasma discharge and the presence of said structure facilitates the establishment of said discharge by concentrating an electric field near a sharp edge of the parasitic mode suppressor.

12 . The resonator as claimed in claim 1 , the parasitic mode suppressor further comprising a gas flow channel formed therethrough.

13 . The resonator as claimed in claim 1 , wherein the first mirror is an output coupling mirror and the second mirror is a first multi-folding mirror.

14 . The resonator as claim in claim 13 , further comprising a second multi-folding mirror.

15 . The resonator of claim 14 , wherein at least one of the first and second multi-folding mirrors are curved mirrors.

16 . The resonator of claim 4 , wherein the spacer is a hollow spacer.