Optics solutions supplier Coherent debuted a quad-channel transimpedance amplifier (TIA) designed to power next-generation 800 Gb/s (800G) and 1.6 Tb/s (1.6T) optical transceivers.

The CHR1074 is a current-to-voltage converter, which takes photocurrents (generated from light) from an optical sensor and transforms them into a measurable electrical signal. Current flows through a feedback resistor, where an integrated operational amplifier (opamp) generates a corresponding voltage output proportional to the light intensity.

In the case of 800G and 1.6T optical transceivers, Coherent’s TIA uses a “fast-settling architecture,” meaning it can convert high-speed currents and transform them into electrical signals with high signal integrity.

Hyperscalers – and data center operators with deep enough pockets – are increasingly coveting 1.6T optics to meet the interconnect needs of their high-intensity AI workloads. Marvell, Cisco, Ciena, and Naddod all raced to meet that demand, while Arista, L2Tek, and Carritech Optics moved to capture interest in the slightly more obtainable 800G space.

Coherent’s offering then is engineered to power some of those 800G and 1.6T transceivers.

Specifically, the CHR1074 is designed around what the vendor describes as “burst-mode traffic,” or where sudden, high-volume, short-duration spikes of data occur. The vendor claims traditional TIAs can’t handle such instances, introducing delays when links transition from idle to active.

Coherent claims its TIA can restore full performance during periods of high-burst traffic within 50 nanoseconds, reducing interruptions and ultimately scaling bandwidth.

“AI-driven infrastructure is redefining performance and power requirements across the optical interconnect ecosystem,” Beck Mason, EVP of semiconductor devices at Coherent, explained. “With the CHR1074, Coherent strengthens its leadership in high-speed optical ASICs (application-specific integrated circuits) by delivering both breakthrough performance and system-level efficiency.”

Coherent offers its own line of transceivers marketed towards the AI data center market, with the vendor ramping up shipments of its 1.6T-DR8 line as CEO Jim Anderson said last year was "strong bookings and demand forecasts" from data center customers.