The anisotropy of the second hyperpolarizability of molecular hydrogen from the pressure and temperature dependence of the Kerr effect

Measurements and calculations of the hyperpolarizabilities of atoms and small molecules in the gas phase

“…Since the gas is isotropic, the usual experiments only measure vector and scalar components of the tensors 0 and y (although incoherent light-scattering measurements would be sensitive to higher irreducible tensor components as well). In the case that all applied 0009-2665/94/0794-0003$ 14.00/0 fields have parallel polarization, the measurable quantities are the vector component of the tensor d in the direction of the permanent dipole moment n which defines the molecular z axis, given by = (Y+ + ând the scalar component of the tensor 7, given by the isotropic average '"'ll = + t+ W (5) where ^,v = x,y,z. An alternative notation is 7j = <7>"«, where < ) denotes the isotropic average and z is the space-fixed direction defined by the applied field.…”

On the third-order nonlinear optical responses of cis and trans stilbenes – a quantum chemistry investigation

“…60–62 In this technique, the DC field creates a refractive index difference for the parallel and perpendicular polarization. The γ dc−Kerr (− ω ; ω ,0,0) quantity is determined from analyzing the measured molar Kerr constant: 59,63,64 …”