Acacia Communications intros long-haul coherent CFP, touts Denali DSP customers

Coherent transmission technology vendor Acacia Communications  has unveiled a long-haul version of its AC100-CFP optical transceiver. The company also says “more than 12” customers have adopted Acacia’s Dual-Core Flex-Rate Denali coherent digital signal processor (DSP) in some form.

Like the earlier, metro-focused version of the AC100-CFP, the long-haul optical module incorporates the DSP chip inside the transceiver to create a “digital coherent optics” (DCO) pluggable module. This contrasts to the CFP2 Analog Coherent Optics (CFP2-ACO) transceivers, which rely on board-mounted DSPs. The new CFP-DCO offers improved receiver OSNR performance and will support reaches of 2500 km. It also will support 37.5-GHz channel spacing as well as passive multiplexing in colorless/directionless/contentionless (CDC) ROADM networks, Acacia says. The module is in production, according to an Acacia response to Lightwave queries.

Acacia declined to provide more clarity to the number of customers engaged with the Denali DSP chip beyond the “more than 12” quoted in the company’s press release. However, the company did acknowledge in response to a Lightwave question that these engagements include both use of the device within the flexible-rate AC400 Flex optical module family as well as in standalone form. The DSP enables transmission of three 100G client signals via 2x150G optics and PM-8QAM modulation. Overall, the device will support coherent transmission at rates from 100 to 400 Gbps.

The performance of 150G PM-8QAM meets the majority of our long-haul requirements with a higher spectral efficiency than 100G PM-QPSK and the same optics,” said Mark Filer, senior network engineer, Azure Networking at Microsoft Corp. via the Acacia press release. “Using a common baud rate for all modulation formats, we can fit into 37.5-GHz fixed-grid or colorless ROADM network applications.”

Meanwhile, Acacia says demand for the AC400 modules is strong enough to lead them to add a second contract manufacturer to produce the transceivers.