Preparation, characterization and third order nonlinear optical properties of the bis(tetrabutylammonium)-[Cd(dmit)2] (dmit=2-thioxo-1,3-dithiol-4,5-dithiolate) for all-optical switching applications at blue–green light band

Abstract

Single crystals of (TBA)2[Cd(dmit)2] (TBA=bis-tetrabutylammonium) were prepared and characterized by elemental analyses, proton nuclear magnetic resonance (1HNMR), infrared (IR) and Raman spectra, X-ray powder diffraction spectroscopy and UV–vis–NIR absorption spectrum. Thermal analyses show that (TBA)2[Cd(dmit)2] possesses high thermal stability. The third-order nonlinear optical properties of the crystal in acetonitrile solution were investigated using the laser Z-scan technique with 20ps pulses at 532nm. A typical centro-symmetric profile was observed, which indicates no nonlinear absorption. The magnitudes of third-order nonlinear refraction index n2 and the second order molecular hyperpolarizability γ were 9.409×10−18m2/W and 2.774×10−30esu, respectively, which reveal that the crystal is a potential candidate for application as all-optical switching devices at blue–green light band.