Tatiana B. Andreeva

P‐120: Low Voltage FLC for Fast Active Matrix Displays

The process of FLC director reorientation in alternating electric field is considered for the case, when interaction of FLC molecules with the substrates results in portion unwinding of helix structure and domain walls motion. Hysteresis-free electrooptical response as fast as 30÷70 μs was achieved in FLC cells of 1.0 and 1.3 μm thickness at the electric field intensity of 1.0÷2.0 V/μm. This result is very important for the practical use of FLC materials in fast active matrix displays.

Fast bistable intensive light scattering in helix-free ferroelectric liquid crystals.

A new type of ferroelectric liquid crystal (FLC) is considered, where the reorientation of the director (main optical axes) at the interaction of an electric field with the FLCs spontaneous polarization is due to the movement of spatially localized waves with a stationary profile: solitons arise at the transition due to the Maxwellian mechanism of energy dissipation. Under certain conditions, the appearance of such waves leads to the formation of a structure of transient domains, and as a consequence, to the scattering of light. The Maxwellian mechanism of energy dissipation allows one to reduce the electric field strength at which the maximum efficiency of light scattering is achieved down to 2-3 V/μm and to increase the frequency of light modulation up to 3-5 kHz. Intensive bistable light scattering in an electro-optical cell filled with a specially designed helix-free FLC was studied, and a stable scattering state can be switched on and off for a few tens of microseconds and memorized for a few tens of seconds.

An Effective Method of Suppressing the Speckle-noise Using a Cell with the Helix-free Ferroelectric LC

We suggest a simple and effective method of suppressing the speckle-noise in the lasergenerated images using the high-speed electro-optical cell with the ferroelectric liquid crystal (FLC), in which the helix is absent (compensated). The nature of deformations of FLC smectic layers in the electric field is indicated, and the mechanism of spatially inhomogeneous phase modulation of the laser beam passing through a cell is considered. The results of destruction of the phase relationships in a laser beam and speckle-noise suppressing are presented in comparison with earlier results, when helix FLC was used.

71.3: Invited Paper: Speckle Suppression by Means of Ferroelectric LC Cell

Simultaneous action of low- and high-frequency electric fields on ferroelectric LC cell causes random variations of the refractive index in FLC layer that results in inhomogeneous space and time phase modulation of a laser beam and suppression of speckle- noise in displayed images in real time.