Enhanced operation of tunable dye and Ti:sapphire lasers using a multipass selective reflector

A laser cavity containing highly selective reflector based on a multipass grazing-incidence diffraction grating is described. The operation of the multipass selective reflector (MPSR) is demonstrated and studied experimentally in the case of pulsed dye laser pumped by frequency-doubled Nd:YAG laser. Numerical calculations concerning gain- switched Ti:Sapphire laser with MPSR are also done. An increasing of the spectrally pure output energy more than 5 times is achieved. Decrease of the threshold energy and broadening of the tuning range of several times are also observed depending on the pumping conditions. The calculations show that, in the case of gain-switched Ti:Sapphire laser pumped by Nd:YAG laser, the temporal characteristics of the radiation, the build-up time and the pulse duration are considerably shortened by using MPSR. The improved energy, spectral, and temporal parameters of tunable lasers with MPSR make them suitable for different applications (spectroscopy, biology, DIAL, etc.) as a separate sources or as a part of injection-seeding tunable laser systems.