J. O. Arndt

Faraday effect in TiO2SiO2 glasses

Abstract The Faraday effect in TiO 2 -SiO 2 glasses was monitored by a previously proposed dynamic method. For silica glass (Suprasil 2), the evaluated Verdet constants for wavelengths of 632.8 and 785 nm were found to be (3.930 ± 0.017) × 10 −6 and (3.237 ± 0.068) × 10 −6 (rad/A), respectively. The Verdet constants of ULE glass (Corning, Code 7971) at 632.8 and 785 nm were (3.836 ± 0.064) × 10 −6 and (3.297 ± 0.073) × 10 −6 (rad/A), respectively. With the determined refractive indices, the wavelength-dependent Verdet constant of silica glass was calculated from 213.856 to 6725 nm with the derived equation by means of dispersion theory.

X-ray diffraction of densified silica glass

Abstract X-ray diffraction measurements were performed on silica glasses permanently densified by high pressures. The position q1 of the first sharp diffraction peak (FSDP) of the X-ray structure factor is found to shift to higher values of the scattering vector q as the density of silica glass increases. The height of the FSDP decreases with increasing density. A linear relation between glass density ϱ and q13 is observed upto 15.5% volume densification. The observed linear relation is explained by a distribution of the d-values (dm=2π/q1, where dm is the mean constant of the d-values).

Static dielectric constant and dielectric relaxation of densified SiO2 glass

Abstract An induction method was used to measure the static dielectric constant of densified SiO 2 glass in the time domain. The static dielectric constant is closely associated with glass densification. It decreases with the annealing time of densified silica glass at 1073 K. Through Fourier transformation, dielectric relaxation in the frequency domain can be illustrated. The decrease of static dielectric constant with relaxation of densified glass can be explained by a decrease of polarizable defects in densified silica glass.

Electric potential-related reflection from transparent metal/v-SiO2/metal interfaces

Abstract An interferometric method is proposed to study the electric potential-related reflection from In/v-SiO2/In interfaces. The relationship between reflection intensity and applied electric field strength is derived and applied to study the electro-optic effect and electrostriction in dc- and ac-fields. The variation in reflection intensity originates from electro-optic effect and electrostriction. Relaxation processes are observed in both turn-on and turn-off durations as the rectangular electric field is applied. The reflection signal oscillates at twice the frequency of the applied ac-potential. This method is applicable to study the dielectric relaxation in glasses and optical thin films.

Temperature-dependent optical depolarization in glassy SiO2

Abstract Depolarization experiments were performed on silica glasses (Suprasil 2 and Suprasil W2) to the glass transition temperature. Crystal-like microstructures were observed to exist in silica glasses. The phase transitions were monitored which correspond to α-cristobalite↔β-cristobalite, α-quartz↔β-quartz, β-quartz↔β-tridymite, and α-tridymite↔β-tridymite. The depolarization intensity of polarized He–Ne laser beam appears to exhibit a minimum at 900°C for Suprasil W2, and 800°C for Suprasil 2. The appearance of microstructures and phase transitions depends on thermal history and glass impurities.