Laser-stimulated Pockels effect in CdBr2/Cu polymer nanocomposites

Abstract

Abstract Photostimulated linear electrooptical effects (LEOEs) in the CdBr2/Cu polymer nanocomposites have been established. The phototreatment was carried out using two bicolor coherent beams with Er: glass laser pulses at coherent frequencies 1540 nm and 770 nm. The detection of the LEOE was performed by three wavelengths (633 nm, 1150 nm, and 3390 nm) of continuous-wave (cw) He–Ne laser. The monitoring of the laser-stimulated LEOE has been done immediately after illumination, using the Senarmont method. The fundamental beam was formed by Er: glass laser with pulse time duration about 20 ns and pulse frequency repetition about 10 Hz. The nanocrystallites of the layered crystallites possessed a thickness varying from 1 nm to 200 nm. The contents of the composites have been varied in the polyvinyl alcohol (PVA) matrices. The principal role here is played by Cu ions participating in the ionic conductivity, which favors an internal charged dc-electric field and related photorefraction. The later, in turn, is sensitive to the wavelengths of probing beams. We explored both dependences versus the nanocrystalline thickness as well as the nonlinear optical (NLO) chromophore concentration. This particular study is devoted to the microscopy of the laser-stimulated changes of the crystallites embedded into the matrices.