Three-dimensional direct optical writing and Raman characterization of resulting structural changes in As_2S_3 glasses

摘要

We report on optical writing of typically 300-1000 nm diameter dots within the volume of a bulk As_2S_3 chalcogenide glass using a focused 1-3 mW beam of a cw He-Ne laser. The Raman spectra taken from the dots in the course of the writing indicate that the photorefractivity is manifested by an increased polarizability of bonds within intrinsic As_4S_4 (realgar) groups as well as of S-S bonds within the matrix of the As_2S_3 glass. The photorefractivity is also accompanied by softening of the As-S-As vibrational frequencies, characteristic of AsS_3 pyramids, which are the main structural units of the As_2S_3 glass.