Analysis of a diode-pumped passively Q-switched Nd:GdVO 4 self-stimulating Raman laser

Abstract

This paper presents the theoretical and experimental results of a laser diode-pumped passively Q-switched Nd:GdVO 4 self-Raman laser in detail. In the experiment, by using two Cr 4+:YAG crystals with different initial transmissions as the saturable absorber, using Nd:GdVO 4 as the gain medium and Raman medium simultaneously, the passively Q-switched operation of the Nd:GdVO 4 self-Raman laser at 1176 nm was investigated. The average power, pulse energy, pulse width and pulse repetition rate with respect to the incident pump power were measured. The obtained maximum output average power is 244.6 mW with respect to incident power of 5.7 W and the corresponding conversion efficiency is 4.3%. In the theoretical part, we used the rate equations to obtain the theoretical results. In the rate equations, the Gaussian distributions of the intracavity photon densities of the fundamental and Raman lasers and the initial population-inversion density were taken into account, and the ground-state population density of the saturable absorber at t = 0 is assumed to be uniform. The obtained theoretical results were in agreement with the experimental results on the whole.