Abstract

Wavelength division multiplexing (WDM) is one of the preferred technologies for optical fiber communication networks. A key component in WDM systems that can take advantage of the large bandwidth capacity of fibers, is a wideband tunable optical filter. Various types of filters have been suggested and demonstrated.¹-² However, none of these filters can combine the following three characteristics: low cost, fast tuning speed and low power dissipation. As an inherently inexpensive technology with low power consumption, liquid crystals (LCs) have the potential to fulfill the above three requirements. Tunable LC Fabry-Perot (FP) filters using nematic LCs¹ have tuning speeds on the order of few milliseconds. Chiral smectic A* LCs have microsecond switching speeds, allowing for three orders in magnitude faster tuning over earlier LC filters.

© 1994 Optical Society of America