Abstract

The analysis, design, fabrication, and testing of ferroelectric liquid crystal (FLC) waveguides and waveguide switches are described. The TE, TM, and hybrid modes of propagation for waveguiding in the positive uniaxial FLC film are treated, including the effects of the indium tin oxide electrodes and silicon dioxide buffer layers. Grating coupling to the FLC waveguide is treated and, design for maximum diffraction efficiency is obtained. Two basic types of switch/modulator devices in single-mode waveguides are as follows: 1) cutoff (on-off) attenuation modulator and 2) deflection modulator. In both cases the modulation is produced by electrically switching the optic axis of the FLC by 45°. In the on-off modulator, this causes the propagating mode to be cut off and thus strongly attenuated. In the deflection modulator, this causes a change in the mode index, and thus the output coupled light is deflected through the grating to a new angle. The effects of attenuation in the FLC are included in this work.

© 1992 Optical Society of America