The sysphotonics research group develops systems and algorithms for efficient communication using server-scale, rack-scale and long-haul photonic interconnects. We use these systems to improve the performance of distributed machine learning and planet-scale cloud workloads.
News
2026
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Paper
Two papers accepted to HotNets 2026
Breaking Temporal Symmetry in Collective Communication Algorithms, led by Arjun, and The Case for Automated Probabilistic Reasoning for Network Performance Analysis, with Jamie Kai and Mina Tahmasbi Arashloo.
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Paper
The ACE Center for Evolvable Computing accepted to IEEE Micro
An overview of the SRC/DARPA JUMP 2.0 ACE Center, for the special issue on JUMP 2.0 centers. It includes the group’s work on Morphlux.
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Paper award
λλ wins the Best Paper Award at ACM SIGCOMM 2026!
Vaibhav Mehta and Arjun Devraj’s programming language for silicon photonic switches, with Bill Owens and Justin Hsu. The paper was presented in Denver on August 20.
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Presentation
Eric presents Photonic Rails in ML Datacenters at SIGCOMM 2026 in Denver
Eric gave the Opus talk on August 20.
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Presentation
Lindsey presents a poster at SIGCOMM 2026 in Denver
The Synchronization Tax: How Communication Limits Scaling GPU BW, with Arjun Devraj.
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Talk
Rachee gives the keynote at the first MemNetAI workshop at ACM SIGCOMM 2026
Intelligent Scale-Up Domains for Machine Learning, on August 17 in Denver: why scale-up domains for ML should be rebuilt around photonic interconnects, with demos of GPU failover without moving model weights and of AllReduce done entirely with optical signals. Press coverage: Marvell
Photo: Marvell -
Graduation
Dr. Abhishek Vijaya Kumar starts at Microsoft AI
Abhishek completes his PhD and begins his next chapter at Microsoft AI.
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Fellowship
Keshav Pradeep joins the group as a PhD student and NSF Graduate Research Fellow
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Paper
Two papers accepted to NSDI 2027
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B exam
Congratulations to Abhishek on passing his B exam!
Abhishek defended his thesis, Software-Defined Scale-Up Domains for Machine Learning, on July 8.
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Presentation
Byungsoo and Bhaskar present TVCache: A Tool-Value Cache for Post-Training LLM Agents at ICML 2026 in Seoul
They presented the poster on July 7.
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Paper
Photonic Rails in ML Datacenters accepted to SIGCOMM 2026
Eric Ding, Barry Lyu and Bhaskar Kataria.
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In the news
Cornell Bowers features Arjun in a Student Spotlight
On his OFC 2026 award-winning work using programmable photonics to make distributed ML more efficient.
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Talk
Rachee speaks at the Schmidt Sciences Unconventional Compute Convening in Chicago
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Grant
Rachee receives a Jane Street Research Award
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Graduation
Congratulations to Abhishek on his PhD graduation!
Abhishek was hooded at the Cornell Bowers CS graduation ceremony in Barton Hall on May 23. Next, he is headed to Microsoft AI.
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Research
The team sets up infrastructure for Project Waldo, our Laude Institute Moonshot
Project Waldo builds intelligent agents for remote surgical care with clinicians at Corewell Health in Royal Oak, Michigan.
With Jamal Hashim, Emaad Manzoor and Ryan Madder in the Corewell Health lab 
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A exam
Congratulations to Arjun on passing his A exam!
Arjun presented AI and the Synchronization Tax on May 18.
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Paper
λλ: a programming language for silicon photonics accepted to SIGCOMM 2026
Vaibhav Mehta, Arjun Devraj, Bill Owens and Justin Hsu.
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Teaching
Final exam for CS 4450/5456: Introduction to Computer Networks
The Spring 2026 class takes the final on May 11.
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Paper
TVCache: A Tool-Value Cache for Post-Training LLM Agents accepted to ICML 2026
Abhishek Vijaya Kumar, Bhaskar Kataria, Byungsoo Oh and Emaad Manzoor.
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Presentation
Arjun presents HEDGE: Traffic Engineering with Probabilistic Link Capacities at NSDI 2026 in Renton, WA
Arjun gave the talk on May 5.
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Presentation
Bhaskar presents Learning to Tune Optical WANs: A Field Deployment of Noise Models in Optical Networks at NSDI 2026 in Renton, WA
Bhaskar gave the talk on May 5.
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Grant
Rachee receives a Google Research Award
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Grant
Our group joins the Moonshot cohort funded by the Laude Institute
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Group lunch
Spring group lunch at Rachee’s place
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Paper award
Arjun’s work on in-network analog computing wins the OFC Outstanding Paper Award
In-Network Analog AllReduce for ML with Programmable Integrated Photonics, with Bill Owens and Daniel Perez Lopez, was also an oral and the top-scored paper. Press coverage: Cornell Bowers
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Presentation
Bhaskar presents What Obstructed Skies Teach Us about Satellite Internet at the MIT pod of NINeS 2026
Bhaskar gave the talk on February 10.
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Paper
Reconfigurable Torus Fabrics for Multi-tenant ML accepted to ASPLOS 2026
Abhishek Vijaya Kumar, Eric Ding, Arjun Devraj and Darius Bunandar.
2025
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Paper
What Obstructed Skies Teach Us about Satellite Internet accepted to NINeS 2026
Bhaskar Kataria, with Hammas Bin Tanveer and Rishab Nithyanand.
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Presentation
Jonathan and Byungsoo present FlashMoE: Fast Distributed MoE in a Single Kernel at NeurIPS 2025 in San Diego
They presented the poster on December 5.
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Talk
Rachee gives a talk at IBM Research
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Presentation
Two papers at HotNets 2025
Photonic Rails in ML Datacenters (Eric Ding and Chuhan Ouyang) and Software Managed Networks via Coarsening (with Pradeep Dogga and colleagues).
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Presentation
Eric presents Photonic Rails in ML Datacenters at HotNets 2025 in College Park, MD
Eric gave the talk on November 17.
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Presentation
Pradeep Dogga presents Software Managed Networks via Coarsening at HotNets 2025 in College Park, MD
Pradeep gave the talk on November 17.
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Presentation
Arjun Devraj and Bill Owens.
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Talk
Rachee speaks at the Google Networking Research Summit, Meta and AWS SageMaker
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Paper
FlashMoE: Fast Distributed MoE in a Single Kernel accepted to NeurIPS 2025
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Group lunch
Fall group lunch at Rachee’s place
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Paper
Two papers accepted to NSDI 2026
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Grant
Awarded an NSF grant for efficient collective communication in the cloud
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M exam
Congratulations to Jonathan on passing his M exam!
Jonathan defended his master’s thesis, on FlashDMoE, on May 30.
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Graduation
Congratulations to Jonathan on graduating with his MS!
Jonathan graduated at the Cornell Bowers CS graduation ceremony on May 24. Next, he is headed to Stanford for his PhD.
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Fellowship
Jonathan receives an NSF Graduate Research Fellowship
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Fellowship
Incoming PhD student Lindsey Bowen is named a Cornell Graduate School Dean’s Scholar
Lindsey also receives a Cornell first-year graduate fellowship.
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Presentation
Two papers at OFC 2025
Chip-to-Chip Photonic Connectivity in Multi-Accelerator Servers for ML (Abhishek, Arjun and Darius Bunandar; oral) and PipSwitch: A Circuit Switch Using Programmable Integrated Photonics (Eric Ding).
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Presentation
Abhishek Vijaya Kumar, with Gianni Antichi.
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Presentation
Efficient multi-WAN transport for 5G with OTTER at NSDI 2025
Mary Hogan and colleagues. Gerry Wan presented the paper in Philadelphia on April 29.
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Presentation
Eric presents PipSwitch at OFC 2025 in San Francisco
Eric presented his poster on PipSwitch: A Circuit Switch Using Programmable Integrated Photonics on April 2.
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Field trip
The CS 6458: Systems for Programmable Optical Interconnects class visits the Corning Museum of Glass
The class took a trip on March 17 to see the museum’s exhibit on the history of optical fiber.
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Grant
Rachee receives a Cisco Research Award
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Talk
Abhishek speaks at the Cornell Systems Seminar and to the SRC ACE Center
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Talk
Rachee speaks at the Cisco AI Inference Summit
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Group lunch
Panipuri lunch for the group at Rachee’s place
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Grant
SRC and DARPA fund our group as part of the JUMP 2.0 program
2024
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Grant
The Atkinson Center for Sustainability funds our work on photonic interconnects
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Group outing
Ice cream run with the group
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Presentation
Abhishek presents our vision for server-scale photonic connectivity at HotNets 2024 in Irvine, CA
Abhishek presented A Case for Server-scale Photonic Connectivity on November 18.
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Teaching
TA grading session for CS 4450/5456: Introduction to Computer Networks
The Fall 2024 course staff at a grading session on November 6.
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Talk
Rachee gives talks at Harvard, Brown and MIT
Photonic connectivity within multi-accelerator servers for ML
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Paper
A case for server-scale photonic connectivity accepted to HotNets 2024
Abhishek Vijaya Kumar, Arjun Devraj and Darius Bunandar.
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Grant
A $1M NSF grant (Award #2444537) on chip-to-chip photonic fabrics for ML
From NSF TIP/ITE, to build systems for server-scale photonic interconnects.
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Workshop
Rachee attends the NSF Breaking Low Ideas Lab
The Ideas Lab on Breaking the Low Latency Barrier for Verticals in Next-G Wireless Networks met virtually on July 12 and 19, then in person at Airlie, Virginia, July 22–24.
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Talk
Rachee speaks at AWS SageMaker and the Max Planck Institute summer school
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Talk
Rachee gives a talk at Cisco Research
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Graduation
Congratulations to Soon Jae and Andrii on graduating with their MEng degrees!
Soon Jae Park and Andrii Lermolaiev graduated at the Cornell Bowers CS graduation ceremony on May 25. Next, Soon Jae is headed to d-Matrix and Andrii to Microsoft.
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Teaching
Spring 2024 offering of CS 4450/5456: Introduction to Computer Networks
Rachee’s networking class on May 6, 2024.
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Talk
Rachee gives a talk at the Air Force Research Laboratory, NY
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Presentation
Abhishek presents An Optical Slice of the Wide-Area Network at NSDI 2024 in Santa Clara, CA
Abhishek gave the talk on Chisel on April 17.
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Grant
Rachee receives an Amazon Research Award
2023
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A exam
Congratulations to Abhishek on passing his A exam!
Abhishek presented Photonic Interconnects for Distributed ML on December 5.
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Talk
Rachee gives a talk at Williams College
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Talk
Rachee speaks at the Google Networking Research Summit in Sunnyvale
Rachee presented Photonic Collective Communication for Distributed Machine Learning.
Photo: Justine Sherry -
Grant
Rachee receives a Cisco Research Award
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Presentation
Aashaka Shah presents TACCL: Guiding Collective Algorithm Synthesis using Communication Sketches at NSDI 2023 in Boston
Aashaka gave the talk on April 18.
