Chemical                      ZnGeP2

Density                        4.162  g/cm3

Mohs Hardness             5.5

Surface flatness            <ʎ/4@632.8nm

Surface quality             20-10

Parallelism                   <30 arc sec

Perpendicularity           <5 arc min

Transparency range       0.75 - 12.0

Chamfer                     <0.1 mm x 45°


Due to possessing large nonlinear coefficients (d36=75pm/V), wide infrared transparency range(0.75-12μm), high thermal conductivity(0.35W/(cm·K)), high laser damage threshold (2-5J/cm2)and well machining property, ZnGeP2 crystal was called the king of infrared nonlinear optical crystals and is still the best frequency conversion material for high power, tunable infrared laser generation. 
     Due to these unique properties, it is known as one of the most promising materials for nonlinear optical applications. ZGP can generate 3–5 μm continuous tunable laser out put through the optical parametric oscillation (OPO) technology. Lasers, operating in the atmospheric transmission window of 3–5 μm are of great importance for many applications, such as infrared counter measure, chemical monitoring, medical apparatus, and remote sensing.
     We can offer high optical quality ZGP crystals with extremely low absorption coefficient α < 0.05 cm-1(at pump wavelengths 2.0-2.1 µm), which can be used to generate mid-infrared tunable laser with high efficiency through OPO or OPA processes.

Our Capacity:

     Dynamic Temperature Field Technology was created and applied to synthesize ZGP polycrystalline. Through this technology, more than 500g high purity ZGP polycrystalline with huge grains has been synthesized in one run.
     Horizontal Gradient Freeze method combined with Directional Necking Technology (which can lower the dislocation density efficiently) has been successfully applied to the growth of high quality ZGP crystals.
     The kilogram-level high-quality ZGP crystal with the world's largest diameter (Φ55 mm) has been successfully grown by Vertical Gradient Freeze method.
     The surface roughness and flatness of the crystal devices, less than 5Å and 1/8λ respectively, have been obtained by our trap fine surface treatment technology.
     The final angle deviation of the crystal devices is less than 0.1 degree due to the application of precise orientation and precise cutting techniques.
     The crystal devices with excellent performance have been achieved because of the high quality of the crystals and high-level crystal processing technology (The 3-5μm mid-infrared tunable laser has been generated with the conversion efficiency greater than 56% when pumped by a 2μm light source).
     Our research group, through continuous exploration and technical innovation, has successfully mastered the synthesis technology of high-purity ZGP polycrystalline, the growth technology of large size and high quality ZGP single crystal, and crystal orientation and high-precision processing technology; can provide ZnGeP2 devices and original as-grown crystals in mass scale with high uniformity, low absorption coefficient, good stability, and high conversion efficiency. At the same time, we have established a whole set of crystal performance testing platform which makes us have the ability to provide crystal performance testing services for customers. 


• 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

• Producing coherent radiation in submillimeterrange from 70.0 µm to 1000 µm

• Generation of combined frequencies of CO2- and CO-lasers radiation and other lasers are working in the crystal transparency region.

The best fit Sellmeier equations:

Basic Properties



Crystal Symmetry and Class

tetragonal, -42m

Lattice Parameters

a =  5.467 Å 

c = 12.736 Å


4.162  g/cm3

Mohs Hardness


Optical Class

Positive uniaxial

Userful Transmission Range

2.0 um - 10.0 um

Thermal Conductivity  
@ T= 293 K

35 W/m∙K (⊥c)
36 W/m∙K ( ∥ c)

Thermal Expansion
@ T = 293 K to 573 K

17.5 x 106 K-1 (⊥c)
15.9 x 106 K-1 ( ∥ c)



Technical Parameters

Diameter Tolerance

+0/-0.1 mm

Length Tolerance

±0.1 mm 

Orientation Tolerance 

<30 arcmin

Surface Quality

20-10 S-D


<λ/4@632.8 nm


<30 arcsec


<5 arcmin


<0.1 mm x 45°

Transparency range 

0.75 - 12.0 ?m

Nonlinear Coefficients

d36 = 68.9 pm/V (at 10.6μm)

d36 = 75.0 pm/V (at 9.6 μm)

Damage Threshold

60 MW/cm2 ,150ns@10.6μm


You can customise this product to your needs. If you do not find suitable specifications for your application please contact us for custom solution.