Technology research institute, CEA-Leti has demonstrated a fullypackaged CWDM optical transceiver module with data transfer of 100Gb/s perfibre, with a low-power-consumption electronic chip co-integrated on thephotonic chip.
The silicon-photonics-based transceiver multiplexes twowavelengths at 50Gb/s. It is designed to meet the increasing data-communicationdemands and energy use of data centres and supercomputers. The institute is part of the COSMICC consortium of key industrialand research partners in silicon photonics, CMOS electronics, packaging,optical transceivers and data centres. Its vision is the mass commercialisationof silicon photonics based transceivers.
EU H2020 project, COSMICC further developed all the requiredbuilding blocks for a transmission rate of 200Gb/s and beyond withouttemperature control with four 50Gb/s wavelengths and by aggregating a largenumber of fibres. The key breakthroughs are the development of broadband andtemperature-insensitive silicon nitride (SiN) multiplexing components onsilicon (Si), the integration of hybrid III-V/Si lasers on the Si/SiN chips anda new high-count adiabatic fiber-coupling technique via SiN and polymerwaveguides.
The researchers say that their demonstration opens the way totechnology that allows a reduction in the cost, the power consumption and thepackaging complexity, allowing a way to reach a very high aggregated data ratebeyond terabits per second.
Using STMicroelectronics’ silicon photonics integrationplatform, the COSMICC project developed a coarse wavelength divisionmultiplexing (CWDM) silicon-photonics transceiver in a packaged module at100Gb/s per fibre. This is scalable to 400Gb/s and includes 3D assembly of asilicon photonic chip and its electronic control chip. The silicon photonicchip integrated high-performance 50Gb/s NRZ optical modulators andphotodetectors, and a two-channel CWDM multiplexer and demultiplexer.
Separately, a library of enabling building blocks for higherdata-rate data centre interconnects was built on a SiN-enhanced siliconphotonics platform, including new broadband and athermal SiN components andhybrid III-V/Si lasers. CEA-Leti scientist Ségolène Olivier, who coordinatedthe EU project, said development of modulators and photodetectors at 50Gb/s andtheir co-integration with their control electronics was a breakthrough that ledto the low-power consumption 100Gb/s transceiver module. ‘In addition,’ shesaid, ‘the new building blocks are essential for addressing the need for Tb/stransceivers at low cost and low energy consumption to sustain the exponentialgrowth of data traffic in datacenters and in high performance computingsystems. COSMICC’s technology will answer tremendous market needs with a targetcost per bit that traditional WDM transceivers cannot meet.’