Open AccessHitless wavelength-selective switch with quadruple series-coupled microring resonators using multiple-quantum-well waveguides
Author(s) -
Hiroshi Kamiya,
Tsuyoshi Goto,
Hiroki Ikehara,
Redouane Katouf,
Taro Arakawa,
Yasuo Kimura
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.020837
Subject(s) - optics , resonator , quantum confined stark effect , optoelectronics , extinction ratio , materials science , wavelength , refractive index , wafer , optical switch , etching (microfabrication) , indium gallium arsenide , quantum well , stark effect , gallium arsenide , electric field , layer (electronics) , physics , laser , nanotechnology , quantum mechanics
We demonstrate a hitless wavelength-selective switch (WSS) based on InGaAs/InAlAs five-layer asymmetric coupled quantum well (FACQW) quadruple series-coupled microring resonators. The WSS is driven by the electric-field-induced change in refractive index in the FACQW core layer caused by the quantum-confined Stark effect (QCSE) for high-speed operation. The WSS with high-mesa waveguides is fabricated on a molecular beam epitaxy-grown wafer by dry etching. The fabricated WSS consists of four microrings, each with a round-trip length of 350 μm and five directional couplers with shallow grooves. A boxlike spectral response and hitless switching with higher extinction ratios than a double series-coupled microring resonator are successfully demonstrated. In addition, we propose the improvement of switching characteristics by controlling the coupling efficiencies at the directional couplers.