<title>Quasi-phase-matched NLO waveguides using periodically corona-poled liquid crystalline polymers</title>

Abstract

Quasi-phasematched (QPM) Second Harmonic Generation (SHG) in poled polymer waveguides has been realised.Rib-waveguide devices were fabricated by lithographic techniques like multilayer spin coating and reactive ion etching, well known from semiconductor technology. Guest-host-systems [Cyanobiphenyl-Polymethylmethacrylat (CN-PMMA)] as wellas co-polymers have been used as the NLO-waveguiding layer between Perfluorcyclobutane (PFCB) layers acting as lower refractive index claddings. Cut-off experiments yield waveguide losses of 3 dB/cm and endfire coupling losses of 3-5 dB. The QPM-period has been determined experimentally to A 20 tm for a 4 tm wide Rib-waveguide by recording Maker fringes. Periodically poled waveguides were realised using Corona poling in combination with corrugated surfaces. The period A of the poling structure was varied continuously between 15 tm and 30 Itm using a fan-shaped corrugation structure. SHG tuning curves exhibit a relative acceptance bandwidth of 3.7 .lO which indicates an effective interaction length 1eff over the full waveguide length of 4 mm.

Science and technology of perfluorocyclobutyl aryl ether polymers

“…Other research groups as well as our own are currently studying PFCB aryl ether polymers for possible EO applications. [120][121][122][123][124][125][126][127][128][129] Our group is currently investigating PFCB aryl ether polymers functionalized with a series of triaryl amino-based chromophores that possess unprecedented hyperpolarizability values (20,000 3 10 À30 esu measured at 1.6 lm). [130][131][132] Liquid Crystalline Polymers Liquid crystalline (LC) polymers are used as displays in electro-optic devices and require interfacial ordering as well as thermal stability; fluoropolymers, in particular, are quite advanced in this respective area.…”