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Optical sub-systems: powering the next generation of coherent transport

How silicon photonics enable the next generation of coherent transceivers

Nokia’s optical sub-systems provide the enabling technology for continued advances in coherent transport, and are at the heart of the photonic service engines (PSE) that power optical network scaling.  Incorporating both Nokia’s Silicon Photonics and coherent DSPs, our Photonic Service Engine family of optical sub-systems continues to enable baud rate scaling, enhanced performance, lower power, smaller form factors, and improved integration of coherent optics.    

Nokia optical subsystems provide leading electro-optics solutions, including both coherent optical subassembly (COSA) components, and integrated pluggable digital coherent optic (DCO) transceiver modules.  Our COSA modules are used in third-party pluggable DCOs, and power a range of 200G and 400G DCOs in QSFP-DD and CFP2 form factors.    

Nokia’s pluggable DCOs are used across our optical network platforms, converged IP-optical routing solutions and fixed networks access solutions, and deployed in third-party and white box switches and routers to provide market-leading integrated coherent transport solutions.

How Silicon Photonics enable the next generation of coherent transceivers

Nokia’s Silicon Photonics provide a revolutionary technology platform to enable large-scale integration and scaling of a wide range of optical functions, in much the same way that electronic ASIC integration has increased exponentially over the past 40 years.

Silicon photonics benefit from leveraging the same advanced capabilities of electronic ASIC fabrication facilities to create highly integrated photonic circuits and devices with world-leading performance, and with faster development and manufacturing timelines than is possible with traditional optical materials technologies.

Our Silicon Photonics are integrated with application-optimized coherent digital signal processors (DSPs) which implement sophisticated coherent modem and signal processing algorithms to optimize for maximum performance and lowest power.


Silicon photonics enable complex opto-electronic functions using well-established silicon foundry processes

DCO Module

Silicon Photonics CSTAR COSA optics and integrated multi-function and multi-chip DCO modules


Photonic Service Engine DCOs: electro-optic integrated modules in standardized pluggable QSFP-DD and CFP2 form factors


PSE-V Supercoherent 90Gbaud pluggable DCO deliver record fiber capacity performance in real-world long-haul optical networks, and have demonstrated 400G over 10,000km subsea links

Silicon Photonics provide the ability to integrate complex optical, opto-electronic and electronic functions needed in a coherent transceiver, in ways that simply could never be addressed using discrete devices. The co-design, co-packaging and multi-chip integration of silicon photonic integrated circuits (PICs) with mixed-signal RF integrated circuits (RFICs) and coherent DSPs enables the high-performance high density, low power consumption, and low cost needed for high data rate transceivers operating at 400G, 800G and beyond.


Optical Transmitter/Receiver Optics


The CSTAR-200+ is a small form factor, BGA packaged Silicon Photonics COSA transmitter and receiver for use in 100G/200G DCOs operating up to 34Gbaud. The CSTAR-200+ is designed with high density and low power to enable integration into QSFP-DD, OSFP and CFP2 pluggable form factors for use in 5G fronthaul, access, metro, regional and long-haul applications, or as a COSA module for use in 100/200G coherent on-board optics.



CSTAR™-400 is a next-generation, small form factor BGA packaged, DSP-agnostic Silicon Photonics COSA transmitter and receiver operating up to 69Gbaud and optimized for use in 400G DCOs. The CSTAR-400 is designed with high density and low power to enable integration into QSFP-DD, OSFP and CFP2 pluggable form factors. CSTAR-400 is ideally suited for high-capacity pluggable optics applications such as Data Center Interconnect (DCI) and metro, regional and long-haul transport applications, and for integration into 3rd party 400G DCO modules.

CSTAR Coherent Optics Module datasheet


Pluggable DCO Transceivers

400ZR and 400ZR+

Nokia provides solutions for both 400ZR and 400ZR+ pluggable DCO transceivers in QSFP-DD form factors to enable use in routing and switching platforms with no density penalty versus use of short-reach client “grey” optics.

The QDDCO4Z provides multi-vendor interoperability based on the OIF 400ZR specification, with C-FEC and 16QAM operation supporting single-channel unamplified operation at 400Gb/s up to 40km, and amplified multi-channel operation up to 120km.

The QDDCO4-100G-400G provides interoperability with industry standards such as OIF 400ZR, 400G OpenZR+ and OpenROADM, with o-FEC and variable QPSK/8QAM/16QAM modulation and 30-64Gbaud operation enabling operation at 100Gb/s, 200Gb/s, 300Gb/s and 400Gb/s with hundreds to thousands of kilometers of reach.

Datasheet: Nokia 400ZR/ZR+ coherent modules


400G Multihaul

Nokia’s 400G Multihaul pluggable DCO in a CFP2 pluggable form factor is an ideal choice for scaling network capacity across a wide range of use cases in access, metro aggregation, and metro-regional core networks. Low power consumption and support for both Ethernet and OTN clients provides the flexibility to operate in optical transport systems, router platforms, and other 3rd-party systems.

Nokia’s 400G Multihaul pluggable DCO transceivers support high optical output launch power of 0dBm to enable use across ROADM-enabled networks for maximum network efficiency. Variable baud rate operation from 30 to 69Gbaud and high-order 16QAM modulation to enable efficient network scaling from 100G over thousands of kilometers up to 400 Gb/s per wavelength over several hundreds of kilometers. The C2DCO4 supports interoperability with 400ZR C-FEC and Nokia PSE-2, PSE-3 and PSE-V coherent optics, while the C2DCO4O provides interoperability with industry standards such as OIF 400ZR, 400G OpenZR+ and OpenROADM.

Datasheet: 400G Multihaul CFP2 DCO pluggable transceiver