title: Photosensitive and thermal nonlinear effects in chalcogenide photonic crystal cavities.
abstract: We investigate the photosensitive and thermo-optic nonlinear properties of chalcogenide glass photonic crystal (PhC) cavities at telecommunications wavelengths. We observe a photosensitive refractive index change in AMTIR-1 (Ge(33)As(12)Se(55)) material in the near-infrared, which is enhanced by light localization in the PhC cavity and manifests in a permanent blue-shift of the nanocavity resonance. Thermo-optic non-linear properties are thoroughly investigated by i) carrying out thermal bistable switching experiments, from which we determined thermal switching times of 63 μs and 93 μs for switch on and switch off respectively and ii) by studying heating of the cavity with a high peak power pulsed laser input, which shows that two-photon absorption is the dominant heating mechanism. Our measurements and analysis highlight the detrimental impact of near-infrared photosensitivity and two-photon absorption on cavity based nonlinear optical switching schemes. We conclude that glass compositions with lower two-photon absorption and more stable properties (reduced photosensitivity) are therefore required for nonlinear applications in chalcogenide photonic crystal cavities.
authors.affiliation: Centre for Ultrahigh-Bandwidth Devices for Optical Systems, Institute for Photonics and Optical Science, School of Physics, University of Sydney, Sydney, NSW 2006, Australia. mlee@physics.usyd.edu.au
authors.forename: Michael W
authors.initials: MW
authors.lastname: Lee
authors.forename: Christian
authors.initials: C
authors.lastname: Grillet
authors.forename: Christelle
authors.initials: C
authors.lastname: Monat
authors.forename: Eric
authors.initials: E
authors.lastname: Mägi
authors.forename: Snjezana
authors.initials: S
authors.lastname: Tomljenovic-Hanic
authors.forename: Xin
authors.initials: X
authors.lastname: Gai
authors.forename: Steve
authors.initials: S
authors.lastname: Madden
authors.forename: Duk-Yong
authors.initials: DY
authors.lastname: Choi
authors.forename: Douglas
authors.initials: D
authors.lastname: Bulla
authors.forename: Barry
authors.initials: B
authors.lastname: Luther-Davies
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Eggleton
mesh_terms: D018011:Chalcogens / Q000737:chemistry*; D003198:Computer Simulation; D017076:Computer-Aided Design; D003460:Crystallization; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D005898:Glass / Q000737:chemistry*; D007259:Infrared Rays; D008027:Light; D008904:Miniaturization; D008962:Models, Theoretical; D017711:Nonlinear Dynamics; D012031:Refractometry / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*; D013696:Temperature
chemical_list: D018011:Chalcogens