Diode-Pumped Passively Q-switched Nd: YLF 1.053μm Laser by Using Cr4+:YAG as a Saturable Absorber

Q-switching of the solid-state lasers is important because it provides short duration optical pulses required for laser ranging, nonlinear studies, medicine, and other important applications. The method chosen to switch the Q of the laser cavity greatly influences the size and complexity of the system. Passive Q-switch employing a solid-state saturable absorber is economical, simple and practical. Recently, tetravalent-chromium doped crystals such as Cr4+:YAG, Cr4+:GSGG, Cr4+:Mg2SiO4 and Cr4+:YSGG have been developed, some of them can replace conventional color-center crystals as the saturable absorbers for neodymium lasers.1-4 Unlike the F2- center in LiF crystal, Cr4+ in these crystalline hosts is formed in the specific growth process, therefore it has better long-term stability.