Laser resonator for pulsed excimer laser - has thickness of output-coupling mirror substrate different from that of end mirror

摘要

The resonator for the excimer laser, or another pulsed gas laser, has an output coupling mirror (A) and an end mirror (E), each with a substrate (1, 3). The thickness (DA) of the substrate (1) of the output coupling mirror is different from that (DE) of the substrate (3) of the end mirror. The thickness difference is pref. 0.5 to 3 mm. The different substrate thickness effect with an excimer laser etc. with sufficiently small coherence length that all partial beams (10, 11) have a sufficient path difference so that they do not tend to produce interference. Typical operational thickness difference may be 1 mm. ADVANTAGE - Simple prevention of intensity modulation of laser beam.