Keysight Technologies and Lumentum Holdings have held a joint demonstration of 448 Gbps data transmission using 224 GBaud PAM4 optical technology at the Optical Fiber Communication Conference and Exhibition 2025.
The demonstration addressed the escalating bandwidth demands of artificial intelligence and machine learning applications, enabling the development of power-efficient 3.2 terabit interfaces for future data centre networks.
The demonstration utilised two Keysight M8199B Arbitrary Waveform Generators with NTT’s advanced frequency-domain interleaver to generate 448 Gbps electrical signals with 224 Gbaud PAM4.
This signal is used to drive a Lumentum indium phosphide externally-modulated laser, showcasing the potential for high-speed, power-efficient optical interconnects. Successful generation of 240 Gbaud PAM4 was also demonstrated using the same hardware.
The demonstration featured the latest 224 GBaud and beyond PAM4 technology, which enables 448 Gbps per lane data transmission and paves the way for developing power-efficient 3.2T interfaces for data centre networks. This achievement represents a significant leap forward in achieving higher data rates and improved signal integrity.
The joint demonstration consisted of:
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Keysight’s M8199B Arbitrary Waveform Generator, the industry’s fastest AWG, operating at 256 GSa/s with analog bandwidth exceeding 80 GHz;
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Keysight’s N1032A DCA-X Sampling Oscilloscope, ideal for analysing high baud rate optical signals with up to 120 GHz optical bandwidth;
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NTT’s frequency-domain interleaver, available as Keysight M8159A, which extends the bandwidth of the M8199B AWG; and
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Lumentum’s high-bandwidth InP externally-modulated laser.
“This collaboration showcases the cutting-edge advancements in high-speed optical communication and highlights the combined strengths of Keysight, NTT Innovative Devices, and Lumentum,” said Keysight’s Joachim Peerlings. “This demo is another milestone for Keysight to enable the industry in advancing the AI infrastructure, laying the foundation for future generations to innovate in new and transformative ways.”
Keysight is conducting early stage research and development for 448 Gbps. During this phase, experts explore various modulation schemes, including PAM4, PAM6, and PAM8. Notably, for 224 Gbps optical transmission, the industry has already embraced PAM4 as the preferred choice, highlighting the industry’s commitment to pushing the boundaries of high-speed data transmission and setting new standards for the future.
Artificial intelligence and machine learning applications require ultra-fast, real-time data processing. The 448 Gbps transmission speed accelerates data movement between compute and network nodes, reducing latency and improving AI/ML model efficiency.
As these models become increasingly complex, higher data throughput is essential to support scalability without bottlenecks. Additionally, this breakthrough improves data centre efficiency, lowering operational costs and minimising environmental impact.
“Achieving 448 Gbps transmission is a significant milestone in advancing optical interconnects for AI-driven cloud infrastructure,” said Lumentum’s Matthew Sysak. “This collaboration underscores Lumentum’s expertise in photonics and our commitment to delivering cutting-edge optical components that support the rapid expansion of AI and cloud data centres.”
“As AI and ML applications require real-time processing of ever-growing datasets, our high-performance externally modulated lasers will be instrumental in enabling faster, more efficient, and scalable data centre networks,” he adds.
The Keysight M8199B Arbitrary Waveform Generator and Keysight N1032A/B DCA-X Sampling Oscilloscopes are part of the Keysight artificial intelligence architecture, a portfolio of end-to-end solutions designed to help customers scale artificial intelligence processing capacity in data centres.
