Zinc Germanium Phosphide (ZGP) crystals possessing large nonlinear coefficients (d36=75pm/V). Our ZGP has wide infrared transparency range(0.75-12μm), useful transmission from 1.7um. ZGP also shows high thermal conductivity(0.35W/(cm·K)), high laser damage threshold (2-5J/cm2)and well machining property. ZnGeP2 (ZGP) crystal was called the king of infrared nonlinear optical crystals and it is still the best frequency conversion material for high power, tunable infrared laser generation. DIEN TECH offer high optical quality and large diameter ZGP crystals with extremely low absorption coefficient α < 0.03 cm-1(at pump wavelengths 2.0-2.1 µm). These properties enables ZGP crystal to be used to generate mid-infrared tunable laser with high efficiency through OPO or OPA processes. DIEN TECH provides two types of ZnGeP2 crystal, C-ZGP and YS-ZGP.  YS-ZGP shows lower absorption at 2090nm than C-ZGP. C-ZGP absoprtion coefficient at 2090nm <0.05cm-1 while YS-ZGP absoprtion coefficient at 2090nm <0.02cm-1 . C-ZGP grew by vertical meathod while YS-ZGP grew by horizontal meathod. Also, YS-ZGP shows better homogeneity and output efficiency as well. Applications of ZGP: • Second, third, and fourth harmonic generation of CO2-laser. • Optical parametric generation with pumping at a wavelength of 2.0 µm. • Second harmonic generation of CO-laser. • YS-ZGP are typical material for THz range from 40.0 µm to 1000 µm, pumped by 1um. • Generation of combined frequencies of CO2- and CO-lasers radiation and other lasers are working in the crystal transparency region.   Custom orientations of our ZGP crystals are available on request.