Third-order optical nonlinearities in porphyrins with extended π-electron systems

Abstract

The third-order optical susceptibilities |x3iiii (–3ω; ω, ω, ω)| for spin-coated films of free-base (H2) and MnCl-octaethyl[18]porphyrins, and N, N', N", N'"-tetramethyl-octaethyl[26]porphyrin-bistrifluoroacetate are determined by optical third-harmonic generation measurements at a wavelength of 1907 nm. The |x(3)| values are 1.9 x 10-12, 2.6 × 10-12, and 1.0 × 10-11 esu for H2-[18]porphyrin, MnCl-[18]porphyrin, and [26]porphyrin, respectively. The enhancement of third-order nonlinear properties in macrocyclic compounds is discussed in terms of an extended π-electron system. © 1992 The Japan Society of Applied Physics.