Technology research institute, CEA-Leti has demonstrated a fully packaged CWDM optical transceiver module with data transfer of 100Gb/s per fibre, with a low-power-consumption electronic chip co-integrated on the photonic chip.
The silicon-photonics-based transceiver multiplexes two wavelengths at 50Gb/s. It is designed to meet the increasing data-communication demands and energy use of data centres and supercomputers.
The institute is part of the COSMICC consortium of key industrial and research partners in silicon photonics, CMOS electronics, packaging, optical transceivers and data centres. Its vision is the mass commercialisation of silicon photonics based transceivers.
EU H2020 project, COSMICC further developed all the required building blocks for a transmission rate of 200Gb/s and beyond without temperature control with four 50Gb/s wavelengths and by aggregating a large number of fibres. The key breakthroughs are the development of broadband and temperature-insensitive silicon nitride (SiN) multiplexing components on silicon (Si), the integration of hybrid III-V/Si lasers on the Si/SiN chips and a new high-count adiabatic fiber-coupling technique via SiN and polymer waveguides.
The researchers say that their demonstration opens the way to technology that allows a reduction in the cost, the power consumption and the packaging complexity, allowing a way to reach a very high aggregated data rate beyond terabits per second (Tb/s).
Using STMicroelectronics’ silicon photonics integration platform, the COSMICC project developed a coarse wavelength division multiplexing (CWDM) silicon-photonics transceiver in a packaged module at 100Gb/s per fibre. This is scalable to 400Gb/s and includes 3D assembly of a silicon photonic chip and its electronic control chip. The silicon photonic chip integrated high-performance 50Gb/s NRZ optical modulators and photodetectors, and a two-channel CWDM multiplexer and demultiplexer.
Separately, a library of enabling building blocks for higher data-rate data centre interconnects was built on a SiN-enhanced silicon photonics platform, including new broadband and athermal SiN components and hybrid III-V/Si lasers. CEA-Leti scientist Ségolène Olivier, who coordinated the EU project, said development of modulators and photodetectors at 50Gb/s and their co-integration with their control electronics was a breakthrough that led to the low-power consumption 100Gb/s transceiver module. ‘In addition,’ she said, ‘the new building blocks are essential for addressing the need for Tb/s transceivers at low cost and low energy consumption to sustain the exponential growth of data traffic in datacenters and in high performance computing systems. COSMICC’s technology will answer tremendous market needs with a target cost per bit that traditional WDM transceivers cannot meet.’
