Chromium Doped Yttrium AIuminum Garnet (Cr4+:YAG) crystals are passive elements with excellent optical quality and homogeneity, which serve as excellent Q-switching optics for passively Q-switching diode pumped or lamp-pumped Nd:YAG, Nd:YLF, Yb:YAG or other Nd and Yb doped lasers at wavelength from 1.0 to 1.2 µm. Due to Cr4+:YAG has chemically stable, durable, UV resistant and high damage threshold, it will replace traditional materials, such as, LiF, organic Dye and color centres for passive Q-switching. The good thermal conductivity of Cr4+:YAG is well suited for high average power applications. Also such material can be thermally diffusion bonded to Nd:YAG laser crystals or undoped YAG material with very low loss in the bonding interface section.