News Article
Imec's BOOM project on SOI photonic integration a success
The EU-funded project, which integrated SOI with indium gallium arsenide detectors, has succeeded in developing cheap and power efficient devices for telecoms
Imec and its partners have completed the ‘BOOM’ project funded by the European Union.
The project was coordinated by the National Technical University of Athens (NTUA).
By advancing silicon-on-insulator (SOI) photonic integration technology, compact, cost-effective and power efficient components have been developed. These are envisaged to enable photonic Tb/s capacity systems for current and new generation high-speed broadband core networks.
As part of the project, imec has realised an optical label extractor consisting of a high-resolution demultiplexer integrated with highly efficient InGaAs photodetectors.
Four channel label extractor with four high-finesse ring resonators integrated with InGaAs photodetectors
The BOOM project was focused on the development of a photonic routing platform relying on hybrid SOI integrated photonic ICs to incorporate all the routing functions. These included label detection (imec), control signal generation (HHI, IHP), wavelength conversion (NTUA, TU/e, TU Berlin) and wavelength routing (Lionix, AMO).
Finally, a routing machine with over 160 Gb/s aggregate capacity was built by NTUA and Telecom Italia Lab.
Imec says the project has answered the growing demand for bandwidth hungry internet applications which stresses the available capacity and performance of current optical core networks. Power efficiency, size and equipment costs are key issues in these networks and increasingly more difficult to keep within acceptable limits.
Electronic carrier routing systems consume and dissipate large amounts of electrical power and heat respectively. Bringing photonics technologies deeper and deeper within these routers can improve their performance and decrease power consumption, says imec.
The R & D institute's work within the project focused on the optical label detector. In the proposed routing architecture the optical data packets are labelled with a wavelength code, which has to be extracted from the packet and sent to the routing unit.
The label extractor consists of an optical demultiplexer with very high resolution (12.5 GHz) fabricated on imec 's Silicon photonics platform and integrated with high efficiency InGaAs photodetectors.
Imec adds that reaching the required resolution turned out to be very challenging and needed an in-depth study of silicon micro-ring resonators. The specifications could be met by using single ring resonator based filters.
The ring resonators have integrated resistors, which allow fine tuning of the wavelength channels (bottom electrodes) through the thermo-optic effect. They are connected to evanescently coupled InGaAs photodetectors using the heterogeneous integration technology developed by INTEC, imec’s associated laboratory at Ghent University.
The detectors had an efficiency of close to 1 A/W and were operating at the speed of 1 GBit/s (up to 5 GBit/s). Finally the device was packaged in collaboration with Fraunhofer IZM group based in Berlin. The device is now ready for operation in a system test bed.
The results obtained in the projec,t and in particular the exhaustive study on the micro-ring resonators, are not only relevant for realising the optical label extractor. Imec says they also form an important input for the institute's optical interconnect program which requires high performance demultiplexers for increasing the bandwidth in optical chip-to-chip links. What's more, they could be used in optical sensors and non-linear devices.
