LABORATORY PREPARATION OF HIGHLY PURE AS2SE3 GLASS

Arsenic selenide glass samples have been prepared using a combination of heat treatment and distillation techniques to remove impurities. Tr ansmission spectra of the samples in the infrared region (2.5-20 mu m) were measured. The spectra indicate that the majority of absorbing ox ide species can be removed by a simple heat treatment. Chemical analys is shows that distilled samples contain less silicon impurity, indicat ing that Si is most likely incorporated during tube sealing procedures . Increased transmission for the purified samples in the 10-11 mu m ra nge shows the necessity of purification to obtain glasses with good tr ansparency for CO2 laser applications. The highest transmission values at 10.6 mu m are greater than those suggested by simple theoretical r elations. The high refractive index at this wavelength results in addi tional contributions to the transmitted intensity, most probably due t o sample lensing effects arising from non-parallel sample faces or mis alignment of the sample in the spectrophotometer beam.