title: Integration of GaN/AlN all-optical switch with SiN/AlN waveguide utilizing spot-size conversion.
abstract: Spot-size converters for an all-optical switch utilizing the intersubband transition in GaN/AlN multiple quantum wells are studied with the purpose of reducing operation power by improving the coupling efficiency between the input fiber and the switch. With a stair-like spot-size converter, the absorption saturation of 5 dB is achieved with a pulse energy of 25 pJ. The switch is integrated with a SiN/AlN waveguide and spot-size converters, and the structure provides the possibility of an integration of the switch with other functional devices. To further improve the coupling loss between the waveguide and the switch, triangular-shaped converters are investigated, demonstrating losses as low as 2 dB/facet.
authors.affiliation: Corporate Research & Development Center, Toshiba Corporation,1 Kimukai-Toshiba-cho, Saiwai-ku, Kawasaki 212-8582, Japan. nori-iizuka@toshiba.co.jp
authors.forename: Norio
authors.initials: N
authors.lastname: Iizuka
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Yoshida
authors.forename: Nobuto
authors.initials: N
authors.lastname: Managaki
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Shimizu
authors.forename: Sodabanlu
authors.initials: S
authors.lastname: Hassanet
authors.forename: Chiyasit
authors.initials: C
authors.lastname: Cumtornkittikul
authors.forename: Masakazu
authors.initials: M
authors.lastname: Sugiyama
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nakano
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005708:Gallium / Q000737:chemistry*; D012031:Refractometry / Q000295:instrumentation*; D012666:Semiconductors; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D017655:Silicon Compounds / Q000737:chemistry*
chemical_list: D017607:Aluminum Compounds; D017655:Silicon Compounds; C473348:gallium nitride; C052045:aluminum nitride; D005708:Gallium; C032734:silicon nitride