ECE Seminar: Molly Piels

ECE Seminar: Molly Piels Technical University of Denmark Department of Photonics Engineering Date: Feb. 29, 2016 (Mon.), 11 am Location: 8 St. Mary’s St., PHO 339 Faculty Host: Siddharth Ramachandran Light refreshments will be served outside of PHO 339 at 10:45 am. High-Functionality Photonics for Energy-Efficient Fiber Optic Networks Abstract: The rapid growth of Internet usage over the past two decades has had a dramatic effect on everyday life, but the associated increase in traffic has also placed great strain on existing optical communication infrastructure. Current usage already accounts for 2% of global carbon emissions, and this can only increase if power consumption per bit is not reduced. At the same time, demand for bandwidth is driving providers towards coherent modulation formats with higher spectral efficiency, which require relatively complex and power-hungry receiver architectures and signal processing algorithms. Transmitters and receivers with tunable modulation formats, center wavelengths, and bandwidths have great potential to enable energy savings while keeping pace with increasing traffic by allowing optimization at the larger systems level. In this talk, Piels will discuss enabling technologies for such flexible networks. On the physical layer, bandwidth-tunable coherent receivers require photodiodes with higher speed and higher output power than currently available. Piels will show that the speed and output power can be enhanced by moving from a traditional PIN to a uni-traveling carrier design. Flexible coherent transceivers also require the use of widely tunable lasers, of which the unique phase noise profiles can make traditional carrier recovery algorithms fail. However, using machine learning tools to incorporate known device physics into the carrier recovery algorithm allows receivers based on such lasers to operate. The same machine learning toolkit can also be used to jointly design an analog photonic front end and custom algorithm to further reduce power consumption and enable flexible networks. Speaker Bio: Molly Piels is currently a researcher in the department of photonics engineering at the Technical University of Denmark (DTU Fotonik). She received the M.S. and Ph.D. degrees in electrical engineering in 2009 and 2013 from the University of California Santa Barbara. Her thesis research focused on high-speed high-power photodiodes for photonic integrated circuits in silicon and included the first demonstration of a uni-traveling carrier photodiode in Si/Ge and the first demonstration of an InGaAs photodiode integrated with ultra-low-loss silicon nitride waveguides. At DTU, her work has covered signal processing for coherent communication, space division multiplexing, and photonic integrated circuits. She has written 45 conference and journal papers and is a recipient of a DFF MOBILEX grant. http://www.bu.edu/ece/files/2016/02/MollyPiels-screen.jpg