Measurements of hyperpolarizabilities for some halogenated methanes

Abstract

de Electric-field induced optical second-harmonic generation has been measured for CH4, CH3F, CH2F2, CHF3, CF4, CClF3, and CBrF3. For CH4 and CF4 the third order hyperpolarizability χ( -2ω,0,ω,ω) is obtained directly. For the other (dipolar) molecules, a bond additivity estimate for χ( -2ω; 0, ω, ω) is used to extract the second order hyperpolarizability χ( -2ω,,ω,ω). Results are compared with various data from the literature: calculated hyperpolarizabilities, and measurements of optical harmonic generation, optical mixing and the Kerr effect. The degree of consistency of the experimental data with a bond additivity model is discussed.