ZGP Crystals
What Are ZGP Crystals?
Fig 1. ZnGeP2 single crystals of different sizes. [1]
Zinc germanium phosphide (ZGP, ZnGeP2) is a high-performance nonlinear optical (NLO) crystal widely recognized for its superior properties in the mid-infrared (mid-IR) spectral range. With excellent phase-matching capabilities, large nonlinear coefficients, high laser damage threshold, and wide transmission window (0.74–12 μm), ZGP has become the preferred material for second harmonic generation (SHG), optical parametric oscillation (OPO), optical parametric amplification (OPA), and difference frequency generation (DFG) in the mid-IR. Its combination of wide transparency and strong nonlinear response makes ZGP a critical crystal in defense, scientific research, medical diagnostics, and environmental monitoring.
At Alfa Chemistry, we utilize advanced growth and processing technologies to produce high-quality ZGP crystals that deliver unmatched performance in the most demanding mid-infrared applications.
Features
- Exceptional Nonlinear Coefficients: d36 = 75 pm/V, one of the highest among mid-IR nonlinear crystals.
- Broad Mid-IR Transparency: 0.74 - 12 μm, covering important atmospheric transmission windows.
- High Thermal Conductivity: 180 W/m/K, enabling efficient heat dissipation in high-power applications.
- Excellent Damage Threshold: 30 GW/cm2 (@ 2790 nm, 150 ps), suitable for high-energy laser systems.
- Good Mechanical Properties: Hardness of 5.5-6.0 Mohs for durability and processing.
- High Optical Quality: Excellent homogeneity for efficient frequency conversion.
- Temperature Stability: Consistent performance across operational temperature ranges.
- Large Birefringence: Enables effective phase-matching over a broad spectral range.
Specifications Product Options Applications
| Product Name | ZGP Crystals |
| Catalog No. | OPTIX-0008 |
| Chemical Formula | ZnGeP2 |
| Crystal Structure | Tetragonal system, 42m |
| Lattice Parameters | a=b=5.467Å, c=12.736Å |
| Mass Density | 4.16 g/cm3 |
| Mohs Hardness | 5.5 |
| Melting Point | ~ 1040°C |
| Clear Aperture | > 90% |
| Parallelism | < 20 arc sec |
| Perpendicularity | < 5 arc min |
| Surface Quality (Scratch/Dig) | 20/10, S/D |
| Flatness | < λ/8 @ 632.8nm |
| Thermal Conductivity | 180 W/m/K |
| Thermal Expansion Coefficient | β//, 5×10-6/K; β⊥, 7.8×10-6/K |
| Birefringence | Positive uniaxial |
| Nonlinear Optical Properties |
| NLO Coefficient | d36=75 ± 8 pm/V
Type Ⅰ deeo=d36 sin2θcos2φ
Type Ⅱ doeo =deoo=d36 sinθsin2φ |
| Effective NLO Coefficients | deff = 75 pm/V |
| SHG Phase Matching Range | 3177 ∼10357nm (Type I) |
| Damage Threshold | 30 GW/cm2 (@2790 nm, 150 ps)
1 GW/cm2 (@1060 nm, 2 ns) |
| Linear Optical Properties |
| Transparency Range | 740 – 1200 nm |
| Absorption Coefficient | α<0.05cm-1 @2050-2100 nm |
| Refractive Index | no= 3.1478, ne= 3.1891
no= 3.1333, ne= 3.1744
no= 3.1136, ne= 3.1547
no= 3.0729, ne= 3.1143 |
Note: The data provided is for reference purposes. We recommend consulting with our technical team to verify suitability for your application.
ZGP Crystal Product Options
We offer comprehensive ZGP solutions:
- Available Orientations: [100], [110], [111], custom cuts for specific phase-matching.
- Sizes: Apertures up to 20 × 20 mm² and lengths up to 50 mm; custom sizes on request.
- Surface Finishes: As-cut, polished, AR-coated (custom wavelength ranges).
- Custom Fabrication: Precision cutting, orientation certification, and optical quality testing.
- Specialized Coatings: AR coatings optimized for mid-IR wavelength bands.
- Laser Frequency Conversion: SHG, SFG, DFG in the mid-IR.
- Optical Parametric Devices: OPOs and OPAs for tunable mid-IR sources.
- Defense & Security: IR countermeasures (IRCM) and laser-based detection systems.
- Medical & Biomedical: IR laser sources for diagnostics and surgical tools.
- Spectroscopy & Sensing: Gas detection, environmental monitoring, and chemical analysis.
- Scientific Research: Strong candidate material for next-generation IR laser systems.
Why Choose Our ZGP Crystals?
- Mature Growth Technology: High-quality, large-aperture ZGP crystals are available.
- Rigorous Quality Control: Comprehensive testing for optical homogeneity and performance verification.
- Technical Expertise: Deep knowledge of ZGP properties and mid-IR applications.
- Custom Solutions: Tailored to meet specific medical, or industrial requirements.
- Global Support: Worldwide shipping and technical assistance.
Reference
- Zawilski, Kevin T., et al. Journal of Crystal Growth 310.7-9 (2008): 1891-1896.
