MECHANICALLY INDUCED 2ND-HARMONIC GENERATION IN S-C-ASTERISK ELASTOMERS

A liquid crystalline elastomer (LCE) exhibiting a chiral smectic C pha se (S-c phase) was synthesized and macroscopically ordered by mechani cal deformations. The elastomer displays a permanent noncentrosymmetri c structure and is therefore suitable for second harmonic generation ( SHG) without applying external electrical poling fields. Using the Mak er fringe experiment, the three largest nonlinear optical coefficients d(ig) were measured and the temperature dependence observed. This liq uid-crystal system represents a new class of material for nonlinear op tics.