Temperature dependence of persistent infrared spectral holes for SeH molecules in the GeAsSe glass series

Abstract

Persistent infrared spectral holes have been burned at low temperature into the Se–H stretch mode absorption band of SeH molecules in the GeAsSe-alloy glass series. Eight different compositions have been examined by changing the relative contents of germanium and arsenic covering a range of mean coordination numbers from 2.0 to 2.6. This is the first time that the dephasing time has been examined as a function of the glass coordination number. For all samples a linear dependence between hole width and hole area is found as a function of burn time at constant intensity and temperature, which is then used to extrapolate the hole width to the limit of zero burn time. The temperature dependence of the hole width is found to follow a power law. Both the zero temperature width and the temperature exponent increase with increasing mean coordination number indicating that the vibrational lifetime and the dephasing time may depend on the microscopic topology of the glass rather than on the chemical composition.