Abstimmbare Mikrokristall-Laser

Abstract

Microcrystal lasers are characterized by a resonator mode separation that is of the order of the laser gain bandwidth of the active medium, which is responsible for several interesting laser physical phenomena that can be observed very pronouncedly. Especially by thermally tuning the resonator frequency with respect to the centre-of-gain not only broadly tunable single frequency lasers can be built: the measured data allow the simulation of the microcrystal laser behaviour by means of which optimisation of such lasers can be performed as well as laser performance can be understood better. Microcrystal lasers therefore are a good means to study relevant physical parameters by measuring the phenomena of stimulated emission themselves. This has been already suggested very early by Kamiskii [1] as ‘stimulated emission spectroscopy’, which up to now has been applied to macroscopic laser systems only.

Experiments are described for which a 300 µm cavity length microcrystal resonator was built that was tuneable in single frequency operation over a range of more than 130 GHz at an output power of 23 mW. The characterization of the laser emission includes relaxation oscillation measurements and observation of birefringence effects in Nd:YAG.