The Optical Properties of Liquid Selenium

Abstract

The optical properties of liquid selenium in the near infra-red have been measured for a temperature range up to about 400° C. The absorption edge moves out to longer wavelengths as the temperature increases by an amount corresponding to a change of energy gap of 1.4×10-3 eV/C°. Absorption is very small at low frequencies. For long wavelengths the refractive index decreases as the temperature increases by an amount corresponding to the thermal expansion.