Analysis of actively Q-switched infrared Raman lasers with crystalline media of multi-Raman-modes

Abstract

Actively Q-switched intracavity Raman lasers can generate multi-wavelength infrared laser based on rich modes of crystalline Raman media. Assuming the intracavity photon densities and initial population inversion densities to be of Gaussian spatial distributions, the space-dependent rate equations of actively Q-switched intracavity Raman lasers with two Raman modes are deduced. The rate equations are solved numerically to investigate the influences of normalized variables on pulse energy, peak power, pulse duration, and conversion efficiency of Raman laser outputs, respectively. There are obvious discrepancies between the results of two Raman modes. The dependence of Raman laser conversion efficiency at 1103 nm on normalized initial population inversion density is numerically calculated, the experimental results are consistent with the numerical ones, and the optimum conditions are proposed theoretically in the end.