Abstract

Ferroelectric liquid crystals (FLCs) have advantages for information processing due to their sub­microsecond switching speed, high birefringence and contrast ratio, low-power dissipation, and low cost. We describe a tunable wavelength filter using FLCs. These filters are capable of narrow-bandwidth operation with tunability in the visible and IR spectrums (300 nm to 3 μm). Initial results show high-speed switching between two channels centered at 475 and 625 nm with 50-nm bandwidth. A six-channel filter has been designed with a 10-nm bandwidth and good sidelobe suppression. Experimental data fit extremely well with theoretical prediction as verified by computer simulation. The filter is insensitive to variations of 10% in the FLC device thickness. Applications for the filter include increasing communication channel capacity in broadband user services via wavelength division multiplexing.

© 1988 Optical Society of America