Electronically switchable waveguide Bragg gratings for WDM routing

Just as Bragg gratings are a favored technique for wavelength-selective filtering in optical waveguide systems, switchable Bragg gratings are theoretically an optimum active WDM switching mechanism. To date however, few practical methods for switchable waveguide Bragg gratings are available that combine large dynamic range, index compatibility, good optical quality, and ease of fabrication. Recently, Sutherland and coworkers (1993, 1995, 1997) demonstrated a holographic polymerization process in a polymer-dispersed liquid crystal composite that results in efficient electronically switchable Bragg gratings (ESBG) with low scattering. We report the first waveguide WDM applications.