Direct observation of ultraviolet laser induced photocurrent in oxygen deficient silica and germanosilicate glasses

Bagratashvili, V.N., Tsypina, S.I., Chernov, P.V., Rybaltovskii, A.O., Zavorotny, Y.V., Alimpiev, S.S., Simanovskii, Y.O., Dong, Liang and Russell, P.St. J. (1996) Direct observation of ultraviolet laser induced photocurrent in oxygen deficient silica and germanosilicate glasses. Applied Physics Letters, 68 (12), [1616]. (doi:10.1063/1.115669).

Abstract

UV laser induced ionization of silicon oxygen deficient centers (SODC) in silica glasses and germanium oxygen deficient centers (GODC) in germanosilicate glasses has been studied by direct displacement photocurrent measurements. For both SODC and GODC the two‐photon (two‐step) nature of photoionization has been established. The cross sections of transitions from first excited to upper (ionizable) states were estimated as σ₁₂ = 6×10⁻¹⁸ cm² for SODC and (0.5–1.0)×10⁻¹⁹ cm² for GODC. The effect of pulse‐to‐pulse degradation of the photocurrent signal caused by the screening effect is applied to estimate the lifetimes and ranges of the free carriers. The conclusion was drawn, that ionized SODC and GODC play the key role for free charge trapping.

This record has no associated files available for download.

Contributors

Download statistics