Article
Engineering, Electrical & Electronic
Masahiko Jinno, Itsuki Urashima, Tsubasa Ishikawa, Takahiro Kodama, Yudai Uchida
Summary: This paper presents a novel design of optical spatial switch employing a microlens-based multicore fiber collimator array and a MEMS mirror array. The fabricated prototype demonstrates low insertion loss, low polarization dependent loss, and low crosstalk over a wide wavelength range, making it suitable for spatial channel routing.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Fumi Nakamura, Hideaki Asakura, Keijiro Suzuki, Ken Tanizawa, Minoru Ohtsuka, Nobuyuki Yokoyama, Kazuyuki Matsumaro, Miyoshi Seki, Kazuhiro Ikeda, Shu Namiki, Hitoshi Kawashima, Hiroyuki Tsuda
Summary: A novel 1 x M fold-back type wavelength selective switch (WSS) is designed to have fewer waveguide crossings, reducing excess crosstalk and loss in lightwave circuits. By using a fold-back architecture, the number of crossings can be reduced to less than half of a conventional design, improving performance and scalability. The switching operation of a 200-GHz spacing, 20-channel, 1 x 2 silicon WSS in a fold-back configuration is demonstrated, showing promising results with average insertion loss and extinction ratio.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Ankita Jain, John. C. C. Cartledge
Summary: The impact of filtering impairments resulting from cascaded, wavelength selective switches is investigated for 32 Gbaud dual-polarization 64-ary quadrature amplitude modulation in the presence of transceiver noise. Training-sequence based adaptive equalization and pilot-aided carrier phase estimation are employed to cope with the combined effects of the transceiver-imposed limitation in achievable signal-to-noise ratio and the filtering-induced signal distortion. The implications of statistical variations in the overall filter frequency response are also assessed.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Frank Brueckerhoff-Plueckelmann, Johannes Feldmann, Helge Gehring, Wen Zhou, C. David Wright, Harish Bhaskaran, Wolfram Pernice
Summary: The integration of artificial intelligence systems has led to a significant increase in data generation and processing, requiring compact and energy-efficient hardware. This paper presents an optimized layout for a photonic tensor core (PTC) that performs real-valued matrix vector multiplications at telecommunication wavelengths. The use of phase-change material as an optical attenuator allows for positive-valued multiplications, while a novel symmetric multiplication unit enables the multiplication of arbitrary real factors. The integration of wavelength multiplexers (MUX) and a photonic crossbar array on-chip paves the way for fully integrated systems.
Article
Engineering, Electrical & Electronic
Weigang Hou, Pengxing Guo, Lei Guo, Xu Zhang, Hui Chen, Weichen Liu
Summary: This paper proposes O-Star, a scalable optical switching architecture for on-chip many-core systems. It utilizes hybrid mode and wavelength division multiplexing technology to enable non-blocking switching and parallel data transmission.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Yudai Uchida, Itsuki Urashima, Tsubasa Ishikawa, Shoma Murao, Kyosuke Nakada, Rika Tahara, Yasuki Sakurai, Ryuichi Sugizaki, Masahiko Jinno
Summary: In this paper, we report a 1x8 CSS prototype based on a bundle of three 5-core fibers (5-CFs), which demonstrates the feasibility of a high core count CSS through MCF bundling. The prototype exhibits low insertion loss and polarization dependent loss over a wide wavelength range. The inter-core crosstalk characteristics are thoroughly investigated and shown to be sufficiently low for practical networks. No OSNR penalty was observed when routing multiple signals using the CSS prototype.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Optics
Peng Hao, Zhenchuan Wang, X. Steve Yao
Summary: We propose and demonstrate a Lidar beam-forming scheme using wavelength-division-multiplexing (WDM) and time-division-multiplexing (TDM), which eliminates the need for moving parts. The scheme achieves beam formation by demultiplexing lights with different wavelengths into N waveguides (WDM channels) and further switching them into M waveguides (TDM channels) to point in different directions. We have successfully demonstrated the scheme using 4 WDM channels and 1 x 4 optical fiber switches, together with time-of-flight (ToF) technique for distance measurement. This combined TDM and WDM scheme offers an attractive alternative to existing beam scanning methods.
OPTICS AND LASERS IN ENGINEERING
(2023)
Article
Engineering, Electrical & Electronic
Taiji Sakamoto, Ryota Imada, Kazuhide Nakajima
Summary: This paper proposes cross-sectional design guidelines suitable for a power efficient cladding-pumped coupled multi-core erbium-doped fiber amplifier (MC-EDFA). Numerical calculations and experimental verification were conducted to investigate the optimal core-to-cladding ratio (R-cc) for achieving high power conversion efficiency (PCE) in different operational bandwidths (C- or L-band) of the amplifier. The results showed that the PCE in the C-band amplifier improves as R-cc increases, whereas the PCE in the L-band amplifier maximizes at a specific R-cc value.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Kazunori Seno, Naru Nemoto, Keita Yamaguchi, Mitsumasa Nakajima, Kenya Suzuki, Yutaka Miyamoto
Summary: The increase in communications network traffic has created a need for larger transmission capacity. The combination of wavelength division multiplexing (WDM) and space-division multiplexing (SDM) is being investigated to meet this demand. Multi-core fiber SDM systems offer increased network flexibility and proportional transmission capacity to the number of SDM channels. However, the increase in input/output ports poses challenges. The spatial and planar optical circuit (SPOC) technology allows for the integration of multiple WSSs and filters, contributing to device miniaturization.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Yudai Uchida, Rika Tahara, Kyosuke Nakada, Msahiko Jinno
Summary: This paper formulates the crosstalk generated in a spatial cross-connect (SXC) based on a core selective switch (CSS), and estimates the maximum number of SXCs through which an optical signal can pass by applying the crosstalk values obtained from a CSS prototype.
2023 INTERNATIONAL CONFERENCE ON PHOTONICS IN SWITCHING AND COMPUTING, PSC
(2023)
Article
Computer Science, Information Systems
Xiaosong Yu, Shufeng Li, Yongli Zhao, Yuan Cao, Avishek Nag, Jie Zhang
Summary: This study introduces four RCWA algorithms for quantum and classical service requests in multi-core optical networks, each with different functions. Simulation results demonstrate that the RCWA-SP algorithm can improve network performance and reduce blocking probability, while the RCWA-XTP algorithm can reduce inter-core crosstalk.
Article
Engineering, Electrical & Electronic
Yiran Ma, Luke Stewart, Julian Armstrong, Ian G. Clarke, Glenn Baxter
Summary: Wavelength Division Multiplexing (WDM) networks with reconfigurable optical add/drop multiplexers (ROADMs) play a crucial role in meeting increasing bandwidth and routing flexibility demands. The wavelength selective switch (WSS) is a key component in all commercial ROADM systems, with Liquid Crystal on Silicon (LCoS) technology dominating current installations. WSS designs are becoming more specialized for various applications.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Xun Guan, Wei Shi, Leslie Ann Rusch
Summary: Silicon photonics combined with microring modulators can achieve ultra-dense wavelength division multiplexing transmission, enhancing spectral efficiency. The study reports achieving channel spacing comparable to the symbol rate in each WDM channel, reaching 80% spectrum occupation, while also addressing interchannel interference issues.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Z. Huang, S. Yang, Z. Zheng, X. Pan, H. Li, H. Yang
Summary: This paper presents the design, assembly, optimization, and characterization of a twin 1x35 wavelength selective switches (WSSs) using a highly dispersive silicon grating prism (GRISM). The compact WSS reduces the footprint by over 50% while maintaining key performance metrics such as insertion loss, spectral coverage, passband, isolation, etc. It is the most compact high port count WSS demonstrated to date.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Rafael Kraemer, Fumi Nakamura, Menno van den Hout, Sjoerd van der Heide, Chigo Okonkwo, Hiroyuki Tsuda, Antonio Napoli, Nicola Calabretta
Summary: A multi-band photonic integrated wavelength selective switch operating in the O, S, C, and L-bands has been reported, utilizing a folded arrayed-waveguide grating as the filtering element. The operation of the switch was experimentally validated for different bands and modulation formats, demonstrating error-free operation with high data transmission rates in various bands.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)