Measurements of hyperpolarizabilities for some halogenated methanes

Abstract
Dc 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