title: Ultrafast all-optical switch with cross-phase modulation by area-selective ion implantation in InGaAs/AlAsSb coupled double quantum wells.
abstract: We have developed a compact gate switch with monolithic integration of all-optical cross-phase modulation (XPM) in a Mach-Zehnder interferometer (MZI). XPM is caused by intersubband transition (ISBT) in InGaAs/AlAsSb coupled double quantum wells (CDQWs) by area-selective silicon ion implantation and rapid thermal annealing (RTA). While injecting pump light through a transverse electric/transverse magnetic (TE/TM) beam combiner, XPM is induced in one MZI arm and gating operation can be realized. The RTA condition is optimized, and the sample is annealed at 780 °C for 8 s with an implantation dose of 5 × 10(13) cm(-2). Dependence of XPM efficiency on the length of the implanted mesa is also analyzed, and there exists an optimum implantation length to fulfill both high efficiency of ISBT modulation and low loss of the probe and pump signals.
authors.affiliation: Network Photonics Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Jijun
authors.initials: J
authors.lastname: Feng
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Akimoto
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Gozu
authors.forename: Teruo
authors.initials: T
authors.lastname: Mozume
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Hasama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishikawa