Cr4+:YAG  is an ideal material for passive Q-switching of Nd:YAG and other Nd and Yb doped lasers in the wavelength range of 0.8 to 1.2um.It is superior stability and reliability, long service life and high damage threshold. Advantages of Cr4+:YAG • High chemical stability and reliability • Being easy to be operated • High damage threshold (>500MW/cm2) • As high power, solid state and compact passive Q-Switch • Long life time and good thermal conductivity Basic Properties: • Cr 4+ :YAG showed that the pulse width of passively Q-switched lasers could be as short as 5ns for diode pumped Nd:YAG lasers and repetition as high as 10kHz for diode pumped Nd:YVO4 lasers. Furthermore, an efficient green output @ 532nm, and UV output @ 355nm and 266nm were generated, after a subsequent intracavity SHG in KTP or LBO, THG and 4HG in LBO and BBO for diode pumped and passive Q-switched Nd:YAG and Nd:YVO4lasers. • Cr 4+ :YAG is also a laser crystal with tunable output from 1.35 µm to 1.55 µm. It can generate ultrashort pulse laser (to fs pulsed) when pumped by Nd:YAG laser at 1.064 µm.