An F2-excimer laser has multiple closely-spaced spectral lines of interest around 157 nm, and one of the lines is selected by wavelength selection optics. The wavelength selection optics of a first preferred embodiment include a birefringent Brewster window enclosing the laser gas volume of the discharge...http://www.google.com/patents/US6345065?utm_source=gb-gplus-sharePatent US6345065 - F2-laser with line selection
