The nonlinear optical crystal grown from the melt GaSe:AgGaSe2(10%, mass percent) is identified as acentrosymmetric ε-GaSe:Ag(≤0.04%, mass percent) and is used for phase matched frequency conversion. The silver presence results in 30% increase in microhardness, which allows the crystal to be cut and polished at arbitrary direction. The optical properties from visible to mid-IR and further THz ranges are studied in detail. It demonstrates that the absorption coefficient of GaSe:Ag(≤0.04%, mass percent) crystal is twice that of a pure GeSe, and the CO2 laser Second Harmonic Generation(SHG) efficiency is about 1.7 times that of ZnGeP2 crystal.
- AgGaSe crystal
- Optical property
- Second Harmonic Generation(SHG)
- THz range