LARGE KERR EFFECTS IN TRANSPARENT ENCAPSULATED LIQUID-CRYSTALS .2. FREQUENCY-RESPONSE

The encapsulation of liquid crystals in polymer matrices produces materials with interesting electro-optical and scattering properties. When the dispersed phase dimensions are substantially smaller than the incident radiation wavelengths, the material is optically clear with a large Kerr effect. These materials had been shown to behave as orientational Kerr media with Kerr constants as high as 30000 times CS2 [J. Appl. Phys. 67, 4253 (1990)]. In this paper, the frequency response is studied with sinusoidal and pulsed electric fields. The electroactivity rolls off at higher frequencies with the 3 dB point in the range of 2000-12000 Hz depending on liquid crystal loading and temperature. This indicates response times are in the microsecond range which is consistent with the pulsed field data.