Third-Order Optical Nonlinearity of a Novel Material: (Tetramethylammonium)bis(1,3-dithiole-2-thione-4,5-dithiolato) Copper

A novel dmit^2- salt: (tetramethylammonium)bis(1,3-dithiole-2-thione-4,5-dithiolato) copper, abbreviated as MECu, is synthesized and its third-order optical nonlinearity is characterized by Z-scan technique at a wavelength of 1064nm with laser duration of 30ps. Z-scan curves reveal a negative Kerr coefficient at 1064nm and no nonlinear absorption is observed. The nonlinear refraction coefficient n₂ and the second hyperpolarizability γ have been determined to be as large as 2.15×10^-11esu and 3.23×10^-31esu, respectively, suggesting MECu is a potential material for optical device applications.