Abstract

The large third-order nonlinear susceptibility [χ(3)] arising from thermally induced effects in absorbing liquids and liquid crystals (10⁶ or more times greater than that of CS₂) can easily be used to demonstrate and study four-wave mixing processes with low-power lasers. The absorbing liquids provide some advantages over the widely used photorefractive materials in obtaining optical phase conjugation because of their easy availability, low cost, and flexible physical properties. Moreover, the underlying physical mechanism of the thermally induced nonlinearity is one of the best understood of all the nonlinear optical processes, so direct comparison with theory is possible.

© 1986 Optical Society of America