Optical properties of zinc selenide slabs at 373 and 423 K in the wavelength 2–15 μm

Zinc selenide (ZnSe) is a nonlinear optical crystal and infrared optical material, and its window exhibits unique optical properties in the various optical and electronic devices applications. Transmittance spectrum of ZnSe slabs in the infrared wavelength 2–15 μm at normal incidence were investigated by a Bruker V70 FTIR spectrometer. The optical constants of ZnSe at 373 and 423 K were achieved by modeling the transmittance spectrum of ZnSe slab. Then the optical properties of single and double slabs were obtained, including transmittance, reflectance and absorptance. The results show that the shapes of transmittance, reflectance and absorptance spectrum of ZnSe slabs at 373 and 423 K are similar, and single and double ZnSe slabs all have a wide transparent region. With the temperature increasing, the extinction coefficient of ZnSe decreases, but the refractive index of ZnSe increases. The thicker the thickness of ZnSe slab, the weaker the transmittance and reflectance of ZnSe slab, and the stronger the absorptance of ZnSe slab.