Investigation on third-order nonlinear optical properties of two Au(dmit)/PMMA thin films by Z-scan technique in picosecond pulse regime.

The third-order nonlinear optical properties of two Au(dmit)/PMMA compound thin films, hexadecyltrimethylammonium bis(1,3-dithiole-2-thione-4,5-dithiolato)aurate and tetramethylammonium bis(1,3-dithiole-2-thione-4,5-dithiolato)aurate (abbreviated as MeAu and CtAu, respectively) with a doping concentration of 1 wt.% deposited on quartz-glass substrate were characterized by a single beam Z-scan technique at 1064 nm with 20 ps laser pulse width and 10 Hz repetition rate. The dominant nonlinear refraction and tiny nonlinear absorption of both materials lead to a larger possibility for them to be applied as promising candidates of all-optical switching. The results of two figures of merit, | W|≫1 and | T|≪1, were also calculated; this further validated the excellent properties of the materials for applications of the nonlinear optics. [ABSTRACT FROM AUTHOR]