Highly-Integrated CMOS Optical Transceivers

The integration of high-speed optoelectronic transceiver circuits in CMOSis opening up new applications for optical links in data centers, consumer electronics, and automobiles. For ultra lowcost, photodetectors integrated directly on the CMOS die are desirable. Unfortunately, the pn-junctions and depletion regions available in a standard CMOS process have an intrinsic bandwidth of, at most, 10's of MHz, so considerable innovation has been required to make them useful for multi-Gb/s communication. This presentation illustrates that the slowly diffusing photocarriers that usually limit the bandwidth of
photodetectors made in standard CMOS may be considered simply a form of ISI. Hence, the bandwidth limitations of such CMOS photodetectors can be dealt with using signal processing tools similar to
those being applied with success in other wireline communication applications, without requiring special "CMOS photonics" process technologies. A combination of spatially-modulated light detection,
analog equalization, and modest decision feedback equalization appears to offer a path towards data rates in excess of 10-Gbps using standard CMOS photodetectors. Nanoscale CMOS is particularly well
suited to the implementation of such signal processing functions, and prototype results ranging from 0.18um CMOS to 65nm CMOS will be presented. Now, similar techniques are being used to extend the
bandwidth of transceivers designed with discrete but inexpensive optoelectronics (VCSELs, multimode fiber) beyond 40Gb/s/lane without requiring WDM or silicon photonics.

Tony Chan Carusone completed the B.A.Sc. and Ph.D. degrees at the
University of Toronto in 1997 and 2002 respectively. Since 2001, he has
been with the Department of Electrical and Computer Engineering at
the University of Toronto where he is currently a Professor and the
department's Associate Chair, Research. He is a Senior Member of the
IEEE, has co-authored the best paper at the 2005 Compound
Semiconductor Integrated Circuits Symposium, the best student papers
at the 2007, 2008, and 2011 Custom Integrated Circuits Conferences,
and the best invited paper at the 2010 Custom Integrated Circuits
Conference. He was the Editor-in-Chief of the and IEEE Transactions on Circuits and Systems II: Express Briefs
recently served on the analog committee of the International Solid-State Circuits Conference. Currently, he serves on the editorial board of the IEEE Journal of Solid-State Circuits and the Technical Program Committee for the VLSI Circuits Symposium. Tony is the lead author, along with David Johns and Ken Martin, of the 2nd edition of the classic textbook "analog Integrated Circuit Design" .