This exploratory project pushes the limits of current photonic technology.
The ultimate goal of this project is to develop a technology for on-chip integration of ultra-compact nanophotonic circuits for manipulating the light signals, similar to the way electrical signals are manipulated in computer chips.
Integration of optical devices at the chip scale is seen as key to significantly reducing the cost of optical components. Dense photonic integration therefore might enable the whole new area of optical interconnects to be economically viable at different length scales in the systems, between the boards, on the cards and may be eventually even on a computer chip.
The important part of this project is to design and test nanophotonic circuits, which can leverage IBM's expertise in microelectronic circuit fabrication. Eventually the development of the nanophotonic technology compatible with CMOS fabrication line could result in cheap mass production of densely integrated optoelectronic superchips comprising both photonic and electronic circuitry.
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Futuristic silicon chip with monolithically integrated photonic and electronic circuits
This hypothetic chip performs all-optical routing of mutliple N optical channels each supporting 10Gbps data stream. N channels are first demultiplexed in WDM photonic circuit, then rearranged and switched in optical cross-connect OXC module, and multiplexed back into another fiber with new headers in WDM multiplexer. Data packets are buffered in optical delay line if necessary. Channels are monitored with integrated Ge photodetector PD. CMOS logical circuits (VLSI) monitor the performance. Electrical pads are connecting the optoelectronic chip to other chips on a board via electrical signals.
Silicon or more specifically silicon-on-insulator (SOI) is an attractive platform for photonic integration owing to its high refractive index that offers strong light confinement and therefore ultra-compact devices. On the other hand by adopting a substrate material that is CMOS compatible, decades of materials and process knowledge can be leveraged. Feasibly both passive and active optical elements could be combined with electronics on a single chip to achieve monolithic optoelectronic integration.
Last updated 10 Dec 2007