Abstract

We investigated the far UV refractive indices of F-doped SiO₂ glass. The relationship between the refractive index dispersion and F content was revealed in the wavelength range of 230-350 nm. F-SiO₂ glass was prepared by the SiF₄ gas pressure sintering of SiO₂ powder compacts. F content in the resultant glass increased with increasing SiF₄ gas pressure. For example, the F content was measured to be 2.1 wt. % at 1 atm SiF₄ and 3.7 wt. % at 3 atm SiF₄ The refractive indices were measured using the bulk glass specimen (15 × 15 × 15 mm) by means of the minimum deviation method in wavelengths of 235-546 nm. F doping was effective to decrease both the refractive index and the dispersion. The dependence of refractive index on F content was represented as a formula of Δn/n = -0.31c and the dependence of its dispersion was determined as ΔD/D = -1.47c at 250 nm where c is the concentration of F (wt %) and D is dispersion. The resultant data was fitted to a 3-term Sellmeier dispersion relationship and discussed on UV absorption edge of F-doped and pure SiO₂ glass.

© 1989 Optical Society of America