Studies on the first-order hyperpolarizability and terahertz generation in 3-nitroaniline

Single crystals of 3-nitroaniline (C6H6N2O2) also called as m-nitroaniline (m-NA) have been grown by adopting slow evaporation solution growth technique at room temperature using methanol as a solvent. To reveal the microscopic nonlinear optical properties, the first-order hyperpolarizability (β) was evaluated by using the density functional theory (DFT) quantum chemical calculations at B3LYP/3–21 G (d,p) level. According to the results of DFT calculations, the grown crystals exhibit non-zero β values and it might have microscopic nonlinear optical behavior which is seven times more than that of urea. Terahertz (1 THz=1012 Hz) radiation was also generated in the title organic nonlinear optical crystal using ultra short femtosecond laser.