Optical And Physical Properties Of UV-Transmitting Fluorocrown Glasses

Abstract

Glasses based on fluorides are gaining importance because of their special optical properties. These glasses generally have low refractive indices and low dispersions together with low nonlinear refractive indices. Fluorophosphate glasses, moreover, possess anomalous partial dispersions, making them desirable for optical lens designs that reduce the secondary spectrum. In the present investigation a study on a series of five stable glasses which transmit radiation to wavelengths as low as 200 nm is presented. Samples were prepared from 7 kg castings. The properties of the resulting glasses are compared to commercial oxide glasses and crystals. The dispersion and refractive indices in the ultra-violet spectral region of these experimental glasses range between the values for CaF2 and crystalline SiO2. Optical properties such as internal transmittance, UV-cuton, IR-transmission, refractive indices and dispersions at wavelengths in the ultraviolet spectral region are reported for the UV-transmitting glasses. In addition, the glasses were characterized by their physical properties including: transformation temperature, softening point, coefficient of thermal expansion, thermal conductivity, Young's modulus, and Poisson's ratio.