Second Harmonic Generation and Crystal Growth of Chalcone Derivatives

Abstract

The second harmonic generation (SHG) of 55 various substituted chalcones which are quite different from nitroaniline derivatives was studied. A series of chalcones having an alkoxy group, an alkylthio group and a halogen showed relatively high SHG activity and high blue-region transparency. A single crystal with dimensions of up to 45×15×15mm of 4-ethoxy-4′-methoxychalcone was obtained from the solution. The crystal structure was determined to be orthorhombic, Pna2₁. Molecular long axes lay nearly parallel along to the crystallographic _c axis. The cutoff wavelength of the crystal was 430 nm. The effective nonlinear optical susceptibilities, d_eff, Type I and d_eff, Type II were determined to be 4.2 pm/V and 6.5 pm/V, respectively.