Eric T. Prince

Use of Nematic Liquid Crystal Overlayer Cells to Form Planar Waveguide Mach-Zehnder Interferometer and Deflector

Attempts to take advantage of the large electro-optic effect in waveguides formed directly in liquid crystal (LC) films have met with limited success because of large propagation losses associated with thermal fluctuations of the long-range crystal ordering.1 Recently, optical waveguide modulators2 and switches3 have been formed using nematic LC overlayers on passive waveguides. In both cases, the use of LC overlayer cells on passive waveguides significantly reduced propagation losses due to scattering in the liquid crystal. The reduced propagation losses are a direct result of sampling the LC material only via the evanescent portion of the guided light.