Patent ID: 6879616

Claim:
A gas laser comprising: (a) a pair of opposed electrodes comprising an inner and an outer electrode, defining a discharge volume with an inter-electrode gap, each of the pairs of opposed electrodes having a series of saw teeth in a pattern, the inter-electrode gap having first and second opposed ends, the inter-electrode gap having a first dimension at the first end, a second dimension at the second end, and a third dimension at a point between the first end and the second end, the third dimension being less than the first and second dimensions and wherein the gap conforms to a desired mode of the laser between the first end and the second end; and (b) a pair of mirrors, each of the mirrors mounted adjacent to one of the ends for directing light generated in the inter-electrode gap through the discharge volume, wherein the pattern of saw teeth has a depth and a spacing adapted not to impede gain in the desired mode of the laser but to discourage energy build-up in modes of higher order than the desired mode.