Abstract

Due to their spontaneous polar order and high degree of alignment ferroelectric liquid-crystals have recently attracted great interest as promising nonlinear materials. In particular thin layers of chiral (smectic-C^*) molecules sandwiched between two glass slides (cf. Fig. 1) are considered as practical device concepts exhibiting bulk nonlinear response. We have applied optical second-harmonic generation (SHG) to unravel the mechanism of alignment of the liquid-crystalline matrix - a commercial liquid crystal mixture - and its interaction with an added siloxane of high second-order nonlinearity /1/, whose chemical structure is also indicated in Fig. 1.

© 1992 Optical Society of America