Analysis of a diode-pumped Nd : YVO4 laser passively Q switched with GaAs

A diode-pumped Nd : YVO4 laser passively Q switched with GaAs is studied theoretically and experimentally. We have demonstrated the influence of single-photon absorption, two-photon absorption and free-carrier absorption in GaAs on the Q-switched pulse characteristics. The pulse profile, pulse energy and pulse width of the Q switching with GaAs are simulated by using the conventional rate equations of the four-level laser system. The experimental results show reasonable agreement with the theoretical results on the whole. (C) 2001 Published by Elsevier Science Ltd.