OFC 2023: Multiple 800G and modulated laser demo’s from Coherent

Created March 7, 2023
Technologies and Products

Coherent is demonstrating an optical transceiver module operating at 200 Gbps per optical lane, a co-packaged optical (CPO) multimode optical engine operating at 50 Gbps NRZ, and its 200G PAM4 Mach-Zehnder Modulated Laser Technology at this year’s OFC. The company says the pluggable and co-packaged modules embody the next generation of 800 Gbps and 1.6 Tbps optical modules for the data networking industry in single-mode and multimode applications, respectively.

The live transceiver demonstration will showcase an OSFP form factor with 200G PAM4 per lane optical and 100G PAM4 per lane electrical interfaces, with an optical reach of up to 2 km and is aimed at the next generation of 25T and 50T Ethernet switches. It represents a natural evolution from transceivers with 100G optical lanes and is more power-efficient and cost-effective than previous generations. The technology is expected to form the core of the second generation of 800G transceivers and the first generation of 1.6T transceivers. Initial applications are anticipated in hyperscale datacentres, with enterprise applications to follow.

Tnhe co-packaged 800G multimode optical engine demonstration will showcase a module that features 16 channels of 50G NRZ transmitters and receivers in a 15 mm x 15 mm x 4 mm multimode CPO 800G VCSEL-based engine. The analogue front end, including the driver, VCSEL, photodiode, and transimpedance amplifier, consumes less than 4 pJ/bit. Each VCSEL is paired with another unpowered device to enable 100% cold sparing for extremely high reliability. Such multimode CPO engines are intended for use in cost-, power-, and latency-sensitive applications such as artificial intelligence and machine learning computer clusters. Prototypes of this multimode CPO engine, which are jointly developed with IBM under the sponsorship of ARPA-E, are available for immediate evaluation.

“These demonstrations will showcase the state of the art in datacom transceiver technology as we approach the era of terabit transmission,” said Dr. Lee Xu, executive vice president, Datacom Transceivers. “Such advances are critical to sustain the accelerating growth of the cloud through power efficiencies and cost reductions at both the module and architecture level.”

The live demonstration of its 200G four-level PAM4 Mach-Zehnder modulated laser technology will showcase a distributed feedback laser and Mach-Zehnder modulator combined monolithically in a photonic integrated circuit that enables 200G PAM4 for 1.6T transceivers with up to 10 km reach.

“This is to our knowledge the industry’s first such laser technology demonstration. We have combined into one PIC the functional elements and integration experience of several of our most advanced devices, which are each breakthrough innovations on their own,” said Dr. Beck Mason, executive vice president, Telecommunications, for Coherent. “This PIC incorporates our knowledge from electro absorption-modulated lasers, IQ modulators for coherent applications, and tuneable lasers with Mach-Zehnder modulators. It will enable higher-performance longer-reach PAM4 optical links.”

Coherent says the differential drive of the DFB-MZ laser achieves superior signal integrity, particularly in higher-density multichannel designs. The DFB-MZ features a channel-specific chirp control that provides excellent dispersion management. The DFB-MZ supports wavelength division multiplexing (WDM), including local area network (LWDM) and coarse (CWDM) wavelength plans. A cooled DFB-MZ supports LWDM for reach up to 10 km. An uncooled DFB-MZ supports CWDM for shorter reaches.

For more information, visit www.coherent.com


This article was written
by Peter Dykes

Peter Dykes is a independent telecoms and technology journalist who has over that last 30 years written for a wide range of B2B publications and companies. A former BT engineer, he specialises in networks and associated support systems. He is currently Editor of Optical Connections.