Specifications:
| Materials | ZnGeP2 crystals | Thickness Tolerance | +/-0.05mm |
| Orientation Tolerance | <0.5° | Flatness | less than λ/8 @ 633nm |
| Transmitting Wavefront Distortion | less than λ/4 @ 633nm | Chamfer | ≤0.2mmx45° |
| Chip | ≤0.1mm | Surface Quality | better than 10/5 S/D (MIL-PRF-13830B) |
| Parallelism | ≤30 arc seconds | Perpendicularity | ≤15 arc minutes |
| Aperture | >90% | ||
Chemical and Physical Properties:
| Chemical Formula | ZnGeP2 | Crystal Structure | Tetragonal, 42m |
| Lattice Parameter | a=b=5.467Å, c=12.736Å | Mass Density | 4.16 g/cm3 |
| Moh Hardness | 5.5 | Melting Point | About 1040°C |
| Thermal Conductivity | 180 W/m/K | Thermal Expansion Coefficient | β,5x10-6 /K; β⊥,7.8x10-6 /K |
| Birefringence | Positive uniaxial | ||
Linear Optical Properties
| Transparency range | 0.74 - 12μm |
| Absorption coefficient | α<0.05cm-1 @2050-2100nm |
| Refractive Indices @ 2.05 μm @ 2.79 μm @ 5.30 μm @ 10.6 μm |
no = 3.1478, ne = 3.1891 no = 3.1333, ne = 3.1744 no = 3.1136, ne = 3.1547 no = 3.0729, ne = 3.1143 |
| Sellmeier Equations(λ in μm) | no2(λ) = 4.64467+5.10087/(λ2-0.13656)+4.27777λ2/(λ2-1653.89) ne2(λ) = 4.71539+5.26358/(λ2-0.14386)+2.37310λ2/(λ2-1000.82) |
Nonlinear Optical Properties
| SHG Phase Matchable | 3177 ∼ 10357nm (Type I) |
| NLO coefficients | d36=75 ± 8 pm/V Type Ⅰ deeo=d36 sin2ϴcos2φ Type Ⅱ doeo=deoo=d36 sinϴsin2φ |
| Damage Threshold | |
| at 2.79 μm | 30 GW/cm2 (150 ps) |
| at 10.6 μm | 1 GW/cm2 (2 ns) |
Modules or Types:
| Modules | Crystal Dimension | Application | Orientation Theta/Phi deg | Coatings |
| SHZGP-7515-54 | 7x5x15mm | OPO @ 2.1-> 3.5-5 µm | 54/0 | AR@2.1µm+BBAR@3.5-5µm |
| SHZGP-7520-54 | 7x5x20mm | OPO @ 2.1-> 3.5-5 µm | 54/0 | AR@2.1µm+BBAR@3.5-5µm |
| SHZGP-7525-54 | 7x5x25mm | OPO @ 2.1-> 3.5-5 µm | 54/0 | AR@2.1µm+BBAR@3.5-5µm |
Zinc germanium phosphide (ZnGeP2) is an excellent mid-IR nonlinear crystal with many outstanding fundamental properties. ZnGeP2 (ZGP) crystal has large nonlinear susceptibility (d36~75 pm/V), which is approximately 160 times that of KDP. ZGP exhibits good optical transparency over the 0.74–12μm wavelength region and relatively high laser damage threshold, and is therefore well suited for producing tunable laser output in the near infrared. ZGP is a very promising material for applications such as SHG, SFG, OPO, and OPG/OPA in the mid-infrared region.
Curves:
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Applications:
