Open AccessDesign and verification of a LO bank enabled by fixed-wavelength lasers and fast tunable silicon ring filters for creating large scale optical switches
Author(s) -
Ryosuke Matsumoto,
Ryotaro Konoike,
Hiroyuki Matsuura,
Keijiro Suzuki,
Takashi Inoue,
Yojiro Mori,
Kazuhiro Ikeda,
Shu Namiki,
Ken-ichi Sato
Publication year - 2021
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.439469
Subject(s) - optical switch , materials science , tunable laser , optics , wavelength division multiplexing , computer science , bandwidth (computing) , optoelectronics , wavelength , telecommunications , physics
The fast and widely tunable wavelength bank is a key enabler in creating wavelength-routing optical switches that do not use fast wavelength tunable lasers. A cost-effective design criterion needs to be developed before it can be applied to intra data center networks. In this paper, we develop a systematic method for designing a wavelength bank that yields high port-count and fast wavelength-routing optical switches for intra data center application. The wavelength bank is created with fixed-wavelength laser sources and wavelength-tunable filters with rapid wavelength selectivity. To optimize the optical switching system that uses the wavelength bank for supplying local oscillator (LO) lights for coherent detection, various parameters are analyzed, including effective bandwidth, laser output power, loss distribution, splitter port count, and optical amplifier gain. We carry out numerical simulations for optimizing the tradeoff between system performance and cost. To verify the designed wavelength bank, a silicon ring filter is newly fabricated with an average fiber-to-fiber insertion loss of 5.3 dB over a 22-nm bandwidth. Using 256-Gb/s DP-QPSK signals, experiments demonstrate a 1,024×1,024 optical switch that uses a fabricated silicon ring filter. The effectiveness of the scalable and fast-tunable LO bank is verified by achieving 262.1-Tb/s switch throughput with switching time under 18 µs.