ANALYSIS AND DESIGN OF WIDELY TUNABLE DIODE-PUMPED CR-LISAF LASERS WITH EXTERNAL GRATING FEEDBACK

We report theoretical and experimental studies on the tuning character istics of a diode-pumped single-longitudinal-mode Cr:LiSAF laser with external optical feedback from a diffraction grating. The results of t heoretical analysis explained the mechanism of wavelength tuning and a greed web with the measured characteristics. The simple relation, whic h describes the dependence of the threshold power on the reflectivity of the output coupler and on the feedback from the grating, was derive d taking account of the wavelength dependence of the Cr:LiSAF emission cross section. From these results we could optimize the reflectivity of the coupler for achieving broad-band tuning. It was found that the tuning range of 200 nm is possible if the feedback ratio from the grat ing is increased to 35%.