We have observed extraordinarily large optical nonlinearity in Methyl Red-doped nematic liquid-crystal film. Grating diffraction can be generated with an optical intensity as low as 40 μW/cm2, and a refractive-index change coefficient of more than 6 cm2/W is obtained. The effect is attributed to formation of an optically induced dc space-charge field and to the resulting reorientation of the highly birefringent nematic director axis.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics