Nonlinear absorption and local coordination of atoms in As_x(GeS₂)_{1 –x}glasses

Abstract

We propose a method to obtain the dynamic specific heat at hundreds of microhertz and higher. This low-frequency measurement is needed in order to gather the data covering the wide frequency dispersion of the dynamic specific heat in the temperature regions of the first-order phase transitions. By using the method, we can use medium-size cylindrical samples, the radius and the thickness of which are several millimetres. Although a sample of this size has the advantage of being easily handled, systematic measurement and analysis using a millimetre-size sample to obtain the low-frequency dynamic specific heat has not been attempted before. We introduce the results of the dynamic specific heat and thermal conductivity at the frequencies from 0.0003 to 0.05 Hz obtained by using the method.

Creation of micro-channels in a photosensitive As 2 S 3 slab waveguide

“…[12][13][14] More recently, the effect of sub-bandgap light was also investigated 15 but, to our knowledge, there has been no clear explanation for the photosensitivity at 800 nm. In one report, 16 the nonlinear absorption at 696 nm was investigated and the authors related it either to a two-photon absorption (TPA) process or a two-step absorption process, leaning toward the latter. However, in other semiconductors, like gallium arsenide, the peak of TPA is at 70% of the wavelength corresponding to half the bandgap, 17 which is around 800 nm for As 2 S 3 .…”