Coherence of XeCl laser radiation

A Michaelson interferometer was used in determination of longitudinal and transverse correlation functions of the radiation field of an XeCl laser. The coherence of the radiation emitted by this excimer laser was investigated. The coherence lengths, radii, and coefficients were determined. The coherence radii were found to be different for different directions across the aperture of the laser beam. The role of coherence of the radiation in the applications of excimer lasers in projection photolithography was analyzed.