Novel Quaternary TlGaSn2Se6 Single Crystal as Promising Material for Laser Operated Infrared Nonlinear Optical Modulators.

The studies of the laser operated third order nonlinear optical features of novel TlGaSn₂Se₆ crystal were done. The main efforts were devoted to a search of a possibility to apply these crystals as laser operated optoelectronic material. For this reason, the third harmonic generation of the Nd:YAG pulse laser 1064 nm as the fundamental beam with varied energy density of up to 200 J/m² was studied. As a source of laser operated light, we have used the cw laser (532 nm), exciting the material above the energy gap. Additionally, the influence of middle-energy Ar+ ions on the XPS spectra of the TlInSn₂Se₆ surface has been explored. We have shown that the main contribution of the Se4p states is manifested in the upper part of the valence band of TlInSn₂Se₆ We have established that for the TlGaSn₂Se₆ crystal there exists a possibility of variation of the third harmonic generation efficiency using illumination by external continuous wave laser beam. The discovered effect makes it possible to utilize TlGaSn₂Se₆ crystal in advanced optoelectronic laser operated devices. [ABSTRACT FROM AUTHOR]