title: Guided-wave liquid-crystal photonics.
abstract: In this paper we review the state of the art in the field of liquid-crystal tunable guided-wave photonic devices, a unique type of fill-once, molecular-level actuated, optofluidic systems. These have recently attracted significant research interest as potential candidates for low-cost, highly functional photonic elements. We cover a full range of structures, which span from micromachined liquid-crystal on silicon devices to periodic structures and liquid-crystal infiltrated photonic crystal fibers, with focus on key-applications for photonics. Various approaches on the control of the LC molecular orientation are assessed, including electro-, thermo- and all-optical switching. Special attention is paid to practical issues regarding liquid-crystal infiltration, molecular alignment and actuation, low-power operation, as well as their integrability in chip-scale or fiber-based devices.
authors: Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi (CNR-IMM), Via del fosso del cavaliere, 100, 00133, Rome, Italy. dimitrios.zografopoulos@artov.imm.cnr.it
authors: D C
authors: DC
authors: Zografopoulos
authors: R
authors: R
authors: Asquini
authors: E E
authors: EE
authors: Kriezis
authors: A
authors: A
authors: d'Alessandro
authors: R
authors: R
authors: Beccherelli