Koichi Wani

Spectrally narrowed lasing of a self-injection KrF excimer laser

Spectrally nantwed lasing of a KrF excimer laser has teen ahieved by a self-injection technique using abeam splitter for power extraction aixi intravity etalons for spectral-narrowing. The laser cavity is divithi into an amplifying branch aix! a spectralnarrowing branch. The spectral bandwidth was narrowed to <3pm FWHM with air-sed etalons placed in the spectral-narrowing branch. A laser propagation model was intrOdUced for describing the laser intensity traveling in the laser cavity. The calculated intensityincident onthe intracavityetalons wassmaller thanthat in theconventional Fabry-Perotcavity withplane-parallel mirrors.

Pressure-controlled wavelength stabilization of a KrF excimer laser with narrowed bandwidth

A spectrally narrowed and wavelength-stabilized KrF excimer laser has been developed. The spectral bandwidth of the laser output was narrowed to 3 pm FWHM using a set of two intracavity air-spaced etalons. An air pressure control system for providing automatic feedback to the intracavity etalons is described. The center wavelength was stabilized to within ±0.5 pm under feedback control both in a continuous running mode and in an intermittent burst mode.