April 16, 2009
Speaker: Miloš Popović, Postdoctoral Associate, MIT
Nanophotonic circuits exploit strong confinement (SC) of light in wavelength-scale waveguides and resonators. They raise the prospect of dense photonic integration on a chip, and of new device concepts with superior performance and novel functionality, based on unique device physics and topologies that become practical in this regime. Nanophotonics has potential to revolutionize current technology in communication, computation and energy conversion, by harnessing large optical bandwidth, energy efficient designs, electronic-photonic integration and all-optical control. However, major challenges to widespread assimilation of SC nanophotonics into mainstream technology have been their extreme sensitivity, and limited scalability and complexity.
In this talk, I first describe SC nanophotonic devices that successfully address the atomic-scale sensitivity and scalability challenges through general physical principles in design. As a result, the first nanophotonic circuits with telecom-grade performance were demonstrated culminating in chip-scale reconfigurable wavelength routers, key enablers for ultrahigh-bandwidth agile optical networks and on-chip interconnects. I show several novel device concepts that go after the limits of bandwidth efficiency, including errorless switches, polarization transparency, loop-coupled resonators, and low-loss Bloch waves.
Next, I address the role of nanophotonics in energy-efficient computation, and describe the first integration of nanophotonics in state-of-the-art, commercial bulk-silicon CMOS processes (65nm node and below) opening the way to large-scale mainstream fabrication of electronic-photonic circuits, and allowing for the first time their full integration in processes compatible with state-of-the-art microprocessors.
Finally, I introduce a new class of nanophotonic circuits based on forces generated by light on the nano scale and movable nanomechanical parts, which promise ground-breaking new possibilities in terms of functionality. The prospect is of light-powered nanomachines and nano-optomechanical self-adaptive photonic circuits with intrinsic feedback control. I describe device concepts enabling picometer-precision positional control of nanomechanical structures, and all-optically self-aligning microresonators that track the wavelength of an incident laser with no external control. These concepts lay the foundation for a fundamentally new class of nanophotonic devices with unique capabilities and numerous new applications.
Miloš Popović got his B.Sc.E. degree in Electrical Engineering at Queen’s University, Canada in 1999, and his M.S. and Ph.D. degrees at Massachusetts Institute of Technology in 2002 and 2007. His graduate work, on strong-confinement nanophotonic circuits, was supervised by Prof. Hermann A. Haus (2000-03), and by Profs. Erich P. Ippen and Franz X. Kärtner (2003-07). He is presently a Postdoctoral Associate at MIT, where he leads as Principal Investigator two research efforts, on nanophotonics for telecom and energy efficient switching, and on optomechanical devices based on light forces. He is also part of research efforts on intrachip photonic networks for multicore processors, and on photonic analog-to-digital converters. His other interests include the theory of linear and nonlinear optical devices; microphotonics-based maskless lithography systems; and energy conversion devices.