Nonlinear Refraction, Excited State Absorption, and Multiphoton Absorption of 1,3-Thiazolium-5-thiolate Mesoionic Compound

We synthesized the mesoionic compound 2-(4-chlorophenyl)-3-methyl-4-(4-methylphenyl)-1,3-thiazole-5-thiolateand measured its refractive and absorptive nonlinear optical responsein different temporal and spectral regimes. The experiments were performedby using the Z-scan technique with two pulsed light sources: the secondharmonic (at 532 nm) of a mode-locked and Q-switched Nd-YAGlaser (100 ps, 10 Hz) and a Ti: Sapphire laser system (100 fs, 1 kHz)operating at 800 nm. The observation and characterization of nonlinearrefraction, two- and three-photon absorption, and excited state absorptionof the mesoionic compound dissolved in dimethyl sulfoxide, in differentconcentrations, are presented and discussed with basis on the populationredistribution in a three-energy-level model that allows the determinationof the parameters which characterize the nonlinear response.

Automated summary

We synthesized a mesoionic compound and investigated its nonlinear optical response in terms of refractive and absorptive properties in different temporal and spectral regimes. Z-scan technique was used with two pulsed light sources: a mode-locked and Q-switched Nd-YAG laser at 532 nm and a Ti: Sapphire laser system at 800 nm. The compound's nonlinear refraction, two- and three-photon absorption, and excited state absorption were observed and characterized based on a three-energy-level model, allowing the determination of the parameters that describe the nonlinear response.