title: Compact silicon photonic waveguide modulator based on the vanadium dioxide metal-insulator phase transition.
abstract: We have integrated lithographically patterned VO2 thin films grown by pulsed laser deposition with silicon-on-insulator photonic waveguides to demonstrate a compact in-line absorption modulator for use in photonic circuits. Using single-mode waveguides at lambda=1550 nm, we show optical modulation of the guided transverse-electric mode of more than 6.5 dB with 2 dB insertion loss over a 2-microm active device length. Loss is determined for devices fabricated on waveguide ring resonators by measuring the resonator spectral response, and a sharp decrease in resonator quality factor is observed above 70 degrees C, consistent with switching of VO2 to its metallic phase. A computational study of device geometry is also presented, and we show that it is possible to more than double the modulation depth with modified device structures.
authors.affiliation: 1Thomas J. Watson Laboratories of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA. rbriggs@caltech.edu
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Briggs
authors.forename: Imogen M
authors.initials: IM
authors.lastname: Pryce
authors.forename: Harry A
authors.initials: HA
authors.lastname: Atwater
mesh_terms: D017076:Computer-Aided Design; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008670:Metals / Q000737:chemistry; D044367:Phase Transition; D012031:Refractometry / Q000295:instrumentation*; D018511:Systems Integration; D013685:Telecommunications / Q000295:instrumentation*; D017968:Vanadium Compounds / Q000737:chemistry*
chemical_list: D008670:Metals; D017968:Vanadium Compounds; C066075:vanadium pentoxide