News: Optoelectronics
3 April 2025
Keysight and Coherent demo 200G/lane multimode technology at OFC
Keysight Technologies Inc of Santa Rosa, CA, USA and materials, networking and laser technology firm Coherent Corp of Saxonburg, PA, USA have collaborated on a 200G multimode technology demonstration showcased for the first time at the Optical Fiber Communications Conference & Exposition (OFC 2025) in San Francisco (1–3 April). The 200G-per-lane vertical-cavity surface-emitting laser (VCSEL) technology provides higher data transfer rates and addresses industry demand for higher bandwidth in data centers. It should enable the industry to deliver AI/ML services while reducing power consumption and capital expense of short-reach data interconnects.
AI/ML deployment is driving extreme growth in the amount of data transfer in data centers. The cost of optical interconnects is an ever-growing portion of the CapEx of the data center, while the power consumption of the optical interconnects is an ever-growing portion of OpEx. 200G multimode VCSELs can boost data transfer and network efficiency by offering the following benefits compared with single-mode transmission:
- Increased bandwidth: 200Gbps/lane doubles the data throughput of the current highest speed multimode interconnects;
- Power efficiency: Significantly lower power-per-bit relative to single-mode alternatives drives down electrical power operational expense and helps large-scale data centers to minimize their environmental impact;
- Cost efficiency: Multimode VCSELs are less costly to manufacture than single-mode technologies, providing lower capital outlay for short-reach data links;
- Compatible network architecture: AI pods and clusters require many high-speed, short-reach interconnects to share data among GPUs, aligning well with the strength of 200G multimode VCSELs.
The 200G multimode demonstration consists of Keysight’s new wideband multimode sampling oscilloscope technology, Keysight’s M8199B 256GSa/s Arbitrary Waveform Generator (AWG) and Coherent’s 200G multimode VCSEL. The M8199B AWG drives a 106.25GBaud PAM4 electrical signal into the Coherent VCSEL, and the PAM4 optical signal output from the VCSEL is measured on wideband multimode scope displaying the eye diagram. The demo showcases the feasibility and capability of Coherent’s new VCSEL technology as well as Keysight’s ability to characterize and validate this technology.
“Keysight has been a trusted partner and a leader in test instrumentation technology, providing advanced test solutions to us. We rely on Keysight products, such as the M8199B Arbitrary Waveform Generator, to validate our latest transceiver designs,” comments Lee Xu, executive VP & general manager of Coherent’s Datacom business unit. “We look forward to continuing our collaboration as we push the boundaries of optical communications with products based on 200G VCSEL, silicon photonics, and electro-absorption modulated laser (EML),” he adds.
“We are pleased with the progress the industry is making in bringing 200G multimode technology to market. Our close collaboration with Coherent enabled another milestone in high-speed connectivity,” says Dr Joachim Peerlings, VP & general manager of Keysight’s Network and Data Center Solutions Group. “The industry will benefit from a more efficient and cost-effective technology to address their business-critical AI/ML infrastructure deployment in the data center.”
