Key Features of ZnGeP2 Crystal:
- Wide Infrared Transmission Range: ZnGeP2 crystals offer a broad infrared transmission range, making them suitable for various IR optical applications.
- High Nonlinear Coefficient: These crystals possess a high nonlinear coefficient (d₃₆ = 75 pm/V at 9.6 µm), enhancing their effectiveness in nonlinear optical applications.
- Excellent Thermal Conductivity: ZnGeP2 crystals exhibit high thermal conductivity, ensuring stability and performance under high-power conditions.
- Low Absorption Coefficient: With a low absorption coefficient (α < 0.02 cm⁻¹ @ 2.0-2.1 µm), these crystals are ideal for high-efficiency optical parametric oscillation and amplification.
- High Damage Threshold: These crystals can withstand high power densities, making them robust and durable for demanding applications.

Description: Zinc Germanium Phosphide (ZnGeP2), abbreviated as ZGP, is renowned for its exceptional infrared transmission range, high nonlinear coefficient, excellent thermal conductivity, and high damage threshold. These properties make ZGP crystals a top choice for mid-IR nonlinear optics, often referred to as the “king of mid-IR nonlinear optical crystals.” Shape Optics offers high-quality ZGP crystals in various sizes, with superior optical properties and low absorption coefficients, making them suitable for a wide range of advanced optical applications.
Applications:
- CO₂ Laser Frequency Doubling, Tripling, and Quadrupling: Enhances laser output efficiency and performance.
- Optical Parametric Oscillation (OPO): Achieves tunable laser output from 2.5-12 µm using 2 µm laser pumping.
- CO Laser Frequency Doubling: Suitable for generating tunable laser output from 40-1000 µm using 1 µm laser pumping.

Our Advantages
Shape Optics offers ZGP crystals under the model YS-ZGP, which stand out due to our unique horizontal growth process, resulting in lower absorption coefficients and higher conversion efficiencies compared to typical vertically grown ZGP crystals.
Comparative Advantages:
- Lower Absorption Coefficient: YS-ZGP crystals exhibit an absorption coefficient α < 0.02 cm⁻¹ @ 2090 nm, significantly lower than the typical α < 0.05 cm⁻¹ @ 2090 nm for conventional ZGP crystals.
- Better Uniformity and Conversion Efficiency: YS-ZGP crystals demonstrate superior uniformity and higher conversion efficiency in practical applications.
Technical Specifications:
| Specification | Value | 
|---|---|
| Flatness | λ/8 at 633 nm | 
| Parallelism | < 20 arcsec | 
| Surface Quality | 10 – 5 scratch & dig (MIL-PRF-13830B) | 
| Perpendicularity | < 5 arcmin | 
| Angle Tolerance | < 30 arcmin | 
| Aperture Tolerance | ± 0.1 mm | 
| Clear Aperture | 90% of full aperture | 
Physical Properties
| Property | Value | 
|---|---|
| Chemical Formula | ZnGeP₂ | 
| Density, g/cm³ | 4.162 | 
| Mohs Hardness | 5.5 | 
| Crystal Structure | Orthorhombic | 
| Space Group | Pna2₁ | 
| Lattice Constants, Å | a = 6.404, b = 10.616, c = 12.814, z = 8 | 
| Melting Point, °C | 1172 | 
| Transition Temperature, °C | 936 | 
| Thermal Expansion Coefficients, °C⁻¹ | aₓ = 11×10⁻⁶, aᵧ = 9×10⁻⁶, a𝓏 = 0.6×10⁻⁶ | 
| Thermal Conductivity, W/cm·°C | 13 | 
| Not Hygroscopic | 
Optical Properties
| Property | Value | 
|---|---|
| Transparency Range | 1 – 12 µm | 
| Nonlinear Coefficient | d₃₆ = 75 pm/V @ 9.6 µm | 
| Refractive Indices at 1064 nm | nₒ = 1.744, nₑ = 1.753 | 
| Thermooptic Coefficients | ∂nₓ/∂T = 1.1×10⁻⁵ (K⁻¹), ∂nᵧ/∂T = 1.3×10⁻⁵ (K⁻¹), ∂n𝓏/∂T = 1.6×10⁻⁵ (K⁻¹) | 
| Absorption Coefficient | α < 0.02 cm⁻¹ @ 2.0-2.1 µm | 
| Damage Threshold | 60 MW/cm² @ 10.6 µm, 150 ns | 
| Thermal Conductivity, W/cm·°C | 36 W/mK (⊥c), 7.5×10⁻⁶ K⁻¹ (⊥c), 5.9×10⁻⁶ K⁻¹ (‖c) | 

Nonlinear Properties
| Property | Value | 
|---|---|
| Phase Matching Range for Type 1 SHG in x-y Plane | 0.99–1.08 µm | 
| Phase Matching Range for Type 1 SHG in x-z Plane | 1.1–3.4 µm | 
| Walk-off Angle | 4 mrad | 
| Angular Acceptances | Δθ = 55 mrad × cm | 
| Spectral Acceptance | Δν = 0.56 nm × cm | 
| Effective Nonlinearity | d₃₆ = 75 pm/V @ 9.6 µm | 
| Up to 80% Extractavity SHG Efficiency | |
| Damage Threshold | >60 MW/cm² @ 10.6 µm, 150 ns | 
For more information, please visit our website at Shape Optics or contact us directly to discuss your specific requirements. Shape Optics is your trusted partner for high-quality ZnGeP2 crystals, offering exceptional optical performance and reliability.
 
				




