Command surface induced switching of the optical properties of liquid crystalline thin film structures

• Published in: Synthetic metals Vol. 81; no. 2; pp. 297 - 300
• Main Authors: Knobloch, Harald, Orendi, Horst, Stiller, Burkhard, Büchel, Michael, Knoll, Wolfgang, Seki, Takahiro, Ito, Shinzaburo, Brehmer, Ludwig
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 15-08-1996; Amsterdam Elsevier Science; New York, NY
• Subjects: Application fields; Applied sciences; Circuit properties; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Integrated optics. Optical fibers and wave guides; Liquid crystals; Optical and optoelectronic circuits; Optical properties; Polymer industry, paints, wood; Surfaces; Switching; Technology of polymers; Surfaces; Films; Liquid crystals; Optical properties; Switching; Comb copolymer; Vinyl ester copolymer; Use; Vinyl alcohol copolymer; Photoinduced effect; Guided wave propagation; Experimental study; Thin film; Azo compound; Alignment; Side chain; Optical switching; Time curve; Light sensitive copolymer; Optical waveguide
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/S0379-6779(96)03734-4

We report on optical waveguide structures with light propagation in a nematic liquid crystalline thin film. The liquid crystal (LC) is sandwiched between two so-called photochromic command layers, consisting of a polymer with azobenzene side chains. When exposed to light of appropriate wavelength, the azobenzene side chains undergo a
transcis isomerization process, inducing a homeotropicparallel change in the LC alignment. These orientational changes affect the set of refractive indices of the LC thin film and, hence, can be detected by optical waveguide methods. As a possible application of the command surface effect in optical waveguide structures, we present an optical switching and information storage device.