title: Tunable elastomer-based virtually imaged phased array.
abstract: Virtually imaged phased arrays (VIPAs) offer a high potential for wafer-level integration and superior optical properties compared to conventional gratings. We introduce an elastomer-based tunable VIPA enabling fine tuning of the dispersion characteristics. It consists of a poly-dimethylsiloxane (PDMS) layer sandwiched between silver bottom and top coatings, which form the VIPA's high reflective and semi-transparent mirror, respectively. The latter also acts as an electrode for Joule heating, such that the optical PDMS resonator cavity tuning is carried out via a combination of thermal expansion and the thermo-optic effect. Analogous to the free spectral range (FSR), based on a VIPA specific dispersion law, we introduce a new characteristic VIPA performance measure, namely the free angular range (FAR). We report a tuning span of one FAR achieved by a 7.2K temperature increase of a 170μm PDMS VIPA. Both resonance quality and tunability are analyzed in numerical simulations and experiments.
authors.affiliation: Institute of Electrical and Information Engineering, Christian-Albrechts-Universität zu Kiel, 24143 Kiel, Germany. pm@tf.uni-kiel.de
authors.forename: Philipp
authors.initials: P
authors.lastname: Metz
authors.forename: Hendrik
authors.initials: H
authors.lastname: Block
authors.forename: Christopher
authors.initials: C
authors.lastname: Behnke
authors.forename: Matthias
authors.initials: M
authors.lastname: Krantz
authors.forename: Martina
authors.initials: M
authors.lastname: Gerken
authors.forename: Jost
authors.initials: J
authors.lastname: Adam
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D009757:Nylons / Q000737:chemistry*; D012031:Refractometry / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D004129:Dimethylpolysiloxanes; D009757:Nylons; C085707:poly(dimethylsiloxane)-polyamide copolymer