Nonlinear susceptibilities of vapors and solutions of organic dyes

Abstract

Results of theoretical studies of laser and Kerr nonlinear susceptibilities of vapors and solutions of organic dyes using a series of polycyclic arenes as an example are presented. Nonlinear susceptibilities of the third χ(3) (−3ω; ω, ω, ω) and the fifth χ(5) (−3ω; ω, ω, ω, ω, −ω) orders of a series of organic dyes responsible for third harmonic generation of Nd:YAG laser radiation are calculated within the context of the free electron model. Results of calculations of their Kerr third-order nonlinear susceptibilities χ(3) (−ω; ω, −ω, ω) and non-linear refractive indices n2 are presented. The calculation results are compared with experimental data on third harmonic generation in naphthalene vapors and with χ(3) (−ω; ω, −ω, ω) as well as n2 of paraterphenyl and naphthalene solutions.