Y Synthesis and nonlinear optical properties of 4-phenylethylene derivatives based on a large pi conjugated structure

4-phenylethylene derivatives (B1, B2 and B3) with p conjugated systems were designed and synthesized by Sonogashira coupling reaction and Schiff base reaction. Under the ns laser source, the nonlinear absorption coefficients (beta) of B2 and B3 are 1.85x10(-10) m/W and 1.9x10(-10) m/W. B2 and B3 have good light limit performance. Furthermore, the third harmonic strength of B2 and B3 is 181 and 215 times that of SiO2, respectively. The optical limiting threshold and third harmonic signal show that 4-phenylethylene derivatives will have good application potential in laser protection and frequency conversion. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement