Hyperpolarizability dispersion measured for (CH3)2O.

The third-order nonlinear-optical susceptibility of dimethyl ether, (CH3)2O, has been measured in the gas phase over the wavelength range 488 nm < λ < 1064 nm using the technique of gas-phase electric-field-induced second-harmonic generation with periodic phase matching and with N2 as the reference gas. Measurements span a range of temperature, which allows for separation of the temperature-independent second hyperpolarizability term from the temperature-dependent first hyperpolarizability term. The dispersion curves of the isotropically averaged first and second hyperpolarizabilities (β and γ) are deduced.