Ferroelectric liquid crystals (FLCs) are true liquids with a thermodynamically stable polar structure. Furthermore, in some systems excellent polar stereocontrol has been demonstrated (> 80% of the molecular dipole oriented along the polar axis with infinite “thermal stability”). These properties make FLCs an interesting candidate for second order NLO applications. However, until now the orientation of organic functional arrays with “large β”, typified by the disperse red 1 (DRI) chromophore, has not been demonstrated.
Herein we report the initial results of a study directed towards providing a solution to this problem. Specifically, a new FLC dopant wherein the DRI chromophore (p-nitro-p'-dialkyl-aminoazobenzene unit) is oriented along the polar axis in FLC mixtures up to 30% by weight is described. These results suggest that it will be possible to obtain FLCs with good stereocontrolled orientation of large β functional arrays. Given that hybrid VLSI silicon/FLC optical chips are under intense investigation as micro-displays, and manufacturing issues for this class of devices are being addressed in the display context, the materials presented here suggest VLSI/FLC chips may be useful as high speed electro-optic modulators as well.