LAUSR

Abstract The non-linear optical technology is gaining huge attention to the thermal and mechanical stability, electrical property, and modulate signal flexibility that could be used in uprising optoelectronics devices based on powerful laser technologies such as all optical switches, light-emitting diodes, data storage and optical communication systems. In this paper, selected three phenanthrolines derivatives [2-phenyl-1H-phenanthro[9,10-d]imidazole (1), 2-(4-nitrophenyl)-1H-phenanthro[9,10-d]imidazole(2),2-(4-methoxyphenyl)-1H phenanthro[9,10-d]imidazole (3)] were synthesized and characterized using UV, FT‐IR and 1H NMR. Cubic nonlinear optical properties susceptibility ( χ T H G 3 > ) were analyzed and evaluated using the third harmonic generation technique on thin films at 1064 nm. The investigation study is completed by a theoretical calculation in which the different quantum chemical parameters like frontier molecular orbital analysis, energy gap, dipole moment, average polarizability, and first second hyperpolarizability were analyzed using Density Functional Theory (DFT). The non-linear optical behavior of the selected three phenanthrolines derivatives is confirmed through the obtained high THG efficiency. Moreover, a significant correlation between the molecular structures and the optoelectronic properties is demonstrated.