Query: photonic switch, tolerence

Candidate papers:

abstract: Reconfigurability of photonic integrated circuits (PICs) has become increasingly important due to the growing demands for electronic photonic systems on a chip driven by emerging applications, including neuromorphic computing, quantum information, and microwave photonics. Success in these fields usually requires highly scalable photonic switching units as essential building blocks. Current photonic switches, however, mainly rely on materials with weak, volatile thermo optic or electro optic modulation effects, resulting in large footprints and high energy consumption. As a promising alternative, chalcogenide phase change materials (PCMs) exhibit strong optical modulation in a static, self holding fashion, but the scalability of present PCM integrated photonic applications is still limited by the poor optical or electrical actuation approaches. Here, with phase transitions actuated by in situ silicon PIN diode heaters, scalable nonvolatile electrically reconfigurable photonic switches using PCM clad silicon waveguides and microring resonators are demonstrated. As a result, intrinsically compact and energy efficient switching units operated with low driving voltages, near zero additional loss, and reversible switching with high endurance are obtained in a complementary metal oxide semiconductor (CMOS) compatible process. This work can potentially enable very large scale CMOS integrated programmable electronic photonic systems such as optical neural networks and general purpose integrated photonic processors.
author_names: Jiajiu Zheng

Zhuoran Fang

Changming Wu

Shifeng Zhu

Peipeng Xu

Jonathan K Doylend

Sanchit Deshmukh

Eric Pop

Scott T Dunham

Mo Li

Arka Majumdar
title: Nonvolatile Electrically Reconfigurable Integrated Photonic Switch Enabled by a Silicon PIN Diode Heater.
venue: Advanced materials
year: 2020

abstract: We demonstrate the first multi stage 8 x 8 silicon photonic switch with switching elements based on dual add drop microrings with a compact footprint of 4 mm2. This device leverages co design of the switch architecture and the switching elements with a well balanced set of performance metrics. The switching elements are designed to have a 3 dB optical passband of 165 GHz, exhibiting off and on resonance losses of 0.67 dB and 2 dB, respectively. Full characterization of all switch paths shows an end to end on chip loss between 4.4 and 9.6 dB, with worst case crosstalk leakage averaged at 16 dB. Owing to the efficient doped waveguide thermo optic phase shifters, the device features a tuning efficiency of 48.85 GHz/mW. The reconfiguration time of the switch fabric is measured to be 1.2 ms and 0.5 ms at the rise and fall edge, respectively. The dual microring switching element together with the multi stage architecture preserves an end to end passband over 55 GHz. We validate the switch performance with optical paths of varying numbers of on and off resonance switching elements less than 2 dB power penalties are obtained for all data routings at 32 Gbps.
author_names: Yishen Huang

Qixiang Cheng

Yu-Han Hung

Hang Guan

Xiang Meng

Ari Novack

Matthew Streshinsky

Michael Hochberg

Keren Bergman
title: Multi Stage 8 x 8 Silicon Photonic Switch Based on Dual Microring Switching Elements
venue: Journal of Lightwave Technology
year: 2020

abstract: Disaggregation enabled by silicon photonic switch fabrics is a path to low cost and energy efficient data centers. The routing strategy, which can be seamlessly incorporated into the switch control plane, potentially provides an additional dimension for the physical layer performance optimization, at no extra cost. In this paper, we analyze the role of optical routing strategies for silicon photonic switch fabrics. We define and quantify the number of global switching states in various switching topologies and discuss their relationship to the number of switch permutations. We propose a topology agnostic approach that is shown to optimize fabric wide switch path power penalties and consequently reduce the dynamic range requirement on receivers. Additionally, it potentially compensates for device fabrication variations by taking advantage of the redundancy in switching states over switch permutations; thus, increasing fabrication tolerance. Significant power penalty improvements are demonstrated via both our simulation and test platforms, even for moderate scale silicon switches.
author_names: Qixiang Cheng

Yishen Huang

Hao Yang

Meisam Bahadori

Nathan C Abrams

Xiang-gao Meng

Madeleine Strom Glick

Yang Liu

Michael Hochberg

Keren Bergman
title: Silicon Photonic Switch Topologies and Routing Strategies for Disaggregated Data Centers
venue: IEEE Journal of Selected Topics in Quantum Electronics
year: 2020

abstract: We present a strictly nonblocking $4$ x $4$ electrooptic silicon photonic switch fabric with on chip gain. The switch integrates 12 Mach Zehnder cells in a 3 stage topology equipped with fast electrooptic phase shifters, and thermooptic phase trimmers. To compensate for the losses of the fabric, a 4 channel GaInAsP/InP semiconductor optical amplifier array is flip chip attached into an etched cavity in the silicon photonic chip with butt coupled waveguide interfaces. The chip is wirebonded to a CMOS driver that provides push pull drive to each elementary Mach Zehnder cell. We demonstrate an optical switch assembly with net neutral insertion loss in the C band together with nanosecond scale reconfiguration time.
author_names: Nicolas Dupuis

Fuad E Doany

Russell A Budd

Laurent Schares

Christian W Baks

Daniel M Kuchta

Takako Hirokawa

Benjamin G Lee
title: A $4$ x $4$ Electrooptic Silicon Photonic Switch Fabric With Net Neutral Insertion Loss
year: 2020

abstract: We demonstrate a fully packaged digitally programmable 8x8 strictly nonblocking electrooptic silicon photonics switch module. We measured fiber to fiber loss between 7.5 and 10.5 dB, crosstalk 30 dB, and reconfiguration time 10 ns.
author_names: Nicolas Dupuis

Jonathan E Proesel

Nicolas Boyer

Herschel A Ainspan

Christian W Baks

Fuad E Doany

Elaine Cyr

Benjamin G Lee
title: An 8x8 Silicon Photonic Switch Module with Nanosecond Scale Reconfigurability
venue: 2020 Optical Fiber Communications Conference and Exhibition (OFC)
year: 2020

abstract: Photonic switching technologies show potential for transforming communication networks across diverse markets from long haul to short reach distance scales due to their large bandwidth density, high energy efficiency, and potential for low cost. In recent years, numerous outstanding advancements have been made in scaled silicon photonic switching fabrics: spanning a variety of manufacturing platforms and packaging methods, relying on different switching mechanisms, and assembled on chip in a diverse mixture of loosely related architectures. This paper reviews the current approaches employed by leading researchers in this area, and surveys the state of the art in achieved performance at both the technological and the architectural level. Specifically, we consider thermo optic, electro optic, and MEMS based switch actuation embedded in Mach Zehnder interferometer, ring resonator, and directional coupler based silicon photonic switches. We define common metrics and compare performances. We outline critical requirements for constructing scaled switch fabrics from elementary cells. We investigate similarities and differences between a number of commonly utilized topologies. And, we survey recent accomplishments in scaled switch fabrics at the chip and package level. Moving these demonstrations from research to product will require many further advancements, and we highlight areas that we believe will be critical for market adoption.
author_names: Benjamin G Lee

Nicolas Dupuis
title: Silicon Photonic Switch Fabrics: Technology and Architecture
venue: Journal of Lightwave Technology
year: 2019

abstract: Efficient integrated photonic switches play a critical role in both interchip optical interconnects and data center networks that need to be dynamically reconfigured. Here, we demonstrate a 1 x 2 switch using phase change material Ge Sb Te (GST) combined with a silicon nitride microring resonator. The switch operates by utilizing the dramatic difference in the optical refractive index and extinction coefficient between the crystalline and amorphous phases of GST. By patterning and encapsulating the GST into subwavelength structures, the device achieves a low insertion loss of less than 1 dB in both output ports and can be switched reliably both photothermally and electrothermally.
author_names: Changming Wu

Heshan Yu

Huan Li

Xiaohang Zhang

Ichiro Takeuchi

Mo Li
title: Low Loss Integrated Photonic Switch Using Subwavelength Patterned Phase Change Material
year: 2019

abstract: First demonstration of a dual microring 8x8 silicon photonic switch in a compact 4 mm2 footprint shows 4.4 8.4 dB end to end on chip loss, 16.75 dB first order switching crosstalk, and 40 GHz switching bandwidth capable of high data rate datacenter transmissions.
author_names: Yishen Huang

Qixiang Cheng

Yu-Han Hung

Hang Guan

Ari Novack

Matthew Streshinsky

Michael Hochberg

Keren Bergman
title: Dual Microring Resonator Based 8x8 Silicon Photonic Switch
venue: 2019 Optical Fiber Communications Conference and Exhibition (OFC)
year: 2019

abstract: We present an all digital, fully programmable, nanosecond scale photonic switch platform, monolithically integrating electronics for actuation, tuning, and power monitoring alongside switching elements, resulting in a scalable, packageable solution for high radix photonic switch fabrics. In this platform, we achieve record loss and extinction performances utilizing a 2x2 Mach Zehnder switch (MZS) with 0.8 dB of loss and 28 dB extinction and a 2x2 nested MZS with 1.3 dB of loss and 38 dB extinction.
author_names: Nicolas Dupuis

Jonathan E Proesel

Herschel A Ainspan

Christian W Baks

Mounir Meghelli

Benjamin G Lee
title: Nanosecond photonic switch architectures demonstrated in an all digital monolithic platform.
venue: Optics letters
year: 2019

abstract: The mechanism of Cooper pair formation and its underlying physics has long occupied the investigation into high temperature (high Tc cuprate superconductors. One of the ways to unravel this is to observe the ultrafast response present in the charge carrier dynamics of a photoexcited specimen. This results in an interesting approach to exploit the dissipation less dynamic features of superconductors to be utilized for designing high performance active subwavelength photonic devices with extremely low loss operation. Here, dual channel, ultrafast, all optical switching and modulation between the resistive and the superconducting quantum mechanical phase is experimentally demonstrated. The ultrafast phase switching is demonstrated via modulation of sharp Fano resonance of a high Tc yttrium barium copper oxide (YBCO) superconducting metamaterial device. Upon photoexcitation by femtosecond light pulses, the ultrasensitive cuprate superconductor undergoes dual dissociation relaxation dynamics, with restoration of superconductivity within a cycle, and thereby establishes the existence of dual switching windows within a timescale of 80 ps. Pathways are explored to engineer the secondary dissociation channel which provides unprecedented control over the switching speed. Most importantly, the results envision new ways to accomplish low loss, ultrafast, and ultrasensitive dual channel switching applications that are inaccessible through conventional metallic and dielectric based metamaterials.
author_names: Yogesh Kumar Srivastava

Manukumara Manjappa

Longqing Cong

Harish N S Krishnamoorthy

Vassili Savinov

Prakash Pitchappa

Ranjan Singh
title: A Superconducting Dual Channel Photonic Switch.
venue: Advanced materials
year: 2018