Temperature dependence of the Kerr effect of dimethyl ether

Abstract

Measurements of the Kerr effect (electric birefringence) are reported for gaseous dimethyl ether over the temperature range 259–334 K. The dominant contribution is that in µ²(α₃₃–α)(kT)^–2; α₃₃–α is the difference between the optical polarizability in the direction of the dipole and the mean polarizability at 632.8 nm and is obtained as (–0.53 ± 0.12)× 10^–40 C² m² J^–1. The principal polarizabilities at 632.8 nm are α₁₁=(5.46 ± 0.14)× 10^–40 C² m² J^–1, α₂₂=(6.69 ± 0.17)× 10^–40 C² m² J^–1 and α₃₃=(5.28 ± 0.13)× 10^–40 C² m² J^–1. The first hyperpolarizability β^K contributes –16% of the Kerr constant at 298 K.