Temperature effect on nonlinear refractive indices of liquid crystals in visible and NIR

The effect of temperature variation on nonlinear refractive indices of several types of liquid crystals (LCs) compound has been reported. Birefringence and the temperature gradients of refractive indices of the LCs are determined. Five samples have been investigated; two of them are E7 and MLC 6241-000. The other three have been obtained by mixing the previous two LCs in different proportions. The measurements performed at 632 nm and 1550 nm wavelengths using wedged cell refractometer method. The variation in refractive indices and birefringence were fitted theoretically using the modified Vuks equation. Excellent agreement between the fitted values and experimentally is obtained.