Infrared second-order nonlinear optical effect in Sb2Te3-SrBr2-PbCl2 glass

摘要

A phenomenological and microscopic theory of IR picosecond nonlinear optical response in glass is developed for the middle IR spectral range (5-15 mu m). Both IR-induced second harmonic generation (SHG) as well as linear electrooptic effect (LEOE) were observed. The observed effects arc explained within a framework of fifth-order nonlinear optical susceptibilities. A model that reproduces the basic features of the experimental data, in which are discovered the optical nonlinearities caused by photoinduced electron-phonon anharmonic interactions, is proposed. The role of the IR induced phase matching conditions in the observed phenomena is discussed.