Crystals Land

 

Zinc Selenide (ZnSe)

Zinc selenide is a clear yellow polycrystalline material with a grain size of approximately 70µm, transmitting in the range 0.5-15µm. It is essentially free of extrinsic impurity absorptions, providing extremely low bulk losses from scatter. The main identifiable extrinsic bulk absorption is zinc hydride, whose free diatomic molecule has a vibrational mode at 1608cm^-1. Having a very low absorption of energy makes it useful for optical components in high power laser window and multispectral applications, providing good imaging characteristics. ZnSe is also useful in high resolution thermal imaging systems, where it is used to correct for color distortion which is often inherent in other lenses used in the system. An observed electronic absorption edge at approximately 0.476µm (≈ 2.6eV) at 300K and far infrared multi-phonon absorption edge commencing at approximately 22.2µm.

Main properties:
 

Application fields	IR optics; scintillator; substrates; modulators
Density	5.264 g/cm3
Hardness	105 kg/mm2
Flexural Strength (4pt bending)	7,500 psi
Young’s Modulus	10.2 Mpsi
Poisson Ratio	0.28
Coef. of Thermal Expansion	7.1´10-6/K
Specific Heat	0.339 J/gK
Thermal conductivity	0.16 W/cmK
Dielectric Constant	8.976
Max. Transmittance (l =2.5-15 mm)	³ 70.5 %
Absorption Coef. (l =10.6 mm)	(1-2)´10-3 cm-1 (including 2 surfaces)
Damage threshold (l =10.6 mm)	³ 100 kWt/cm2
Thermo-Optic Coef. (dn/dT)	6.1 ( l =10.6 mm)
Refractive index (l =10.6 mm)	2.4
Electrooptical coefficient (l =10.6 mm)	R41=2.2´10-12 m/V
g-radiation tolerance dose	> 1010 J/kg