Data and Time November 25 , 2010, 4:00-5:00 PM
Location Sanford Flemming Building, Room B560
Host Alex Wong

Integrated Optics: Quest for a Perfect Material

Ksenia Dolgaleva

The Edward S. Rogers Sr. Department of Electrical and Computer Engineering (Photonics)


The demand for high speed and high bandwidth of data transmission in communication systems is rapidly growing.   Electronic processing of optical signals currently used in communication networks requires optical-to-electrical and then back to optical (OEO) conversion, which involves a lot of bulk optical components, separately fabricated, tested, packaged, and then assembled and aligned.  The role of photonic integration at present is to replace the expensive bulk optics in transmitters and receivers by integrated optical circuits containing all the necessary optical components on a single chip.  Practical realization of integrated optics requires a single robust material platform for integrating multiple optical components, including lasers, modulators, detectors, and passive optical devices, on a single chip.  

The projects that I am working on as a postdoc at the University of Toronto are aimed at developing integrated optical devices in aluminum gallium arsenide (AlGaAs).  It is a very promising material for integrated optics due to its mature fabrication technology, multifunctionality, and flexibility in tailoring integrated optical devices.  AlGaAs can serve as an active medium for integrated lasers and detectors, and can also be made passive.  In addition, AlGaAs can exhibit efficient nonlinear interactions with a negligible multiphoton absorption, which is especially important for wavelength conversion devices that are used in wavelength division multiplexing (WDM) communication networks.  It is thus possible to accommodate all types of integrated optical devices on a single chip based on a single material platform. 
In my talk, I will discuss wavelength conversion by cross-phase modulation and four-wave mixing in AlGaAs with a specially designed wafer composition. I will also talk about our recent work on integrated pulse shapers.  These devices have a broad range of applications, including communication networks, nonlinear photonics, signal processing, optical computing, coherent molecular excitation, and many more.  My research is mostly focused on AlGaAs material platform, but we also look into other promising integrated technologies.  I will briefly overview our work on pulse shaping devices in femtosecond-laser-written glass Bragg gratings.  Finally, I will discuss the promise and future directions of integrated optics based on AlGaAs that could potentially become a material platform for all-optical communication systems of the future.


Ksenia Dolgaleva earned her undergraduate degree in Physics from Moscow State niversity, Russia. She was awarded a prize for an outstanding undergraduate thesis from Russian Physical Society. Ksenia has recently completed her Ph.D. program at the Institute of Optics, University of Rochester, USA. There she worked under the supervision of Prof. Robert Boyd on various projects, including composite laser materials, local-field-induced microscopic cascading in nonlinear optics, optical activity in artificial chiral structures, cholesteric liquid crystal laser, and single-step phase-matched third-harmonic generation in a 1D photonic crystal.  Ksenia is currently a postdoctoral fellow at the Department of Electrical and Computer Engineering, University of Toronto, working with Prof. Stewart Aitchison.  Her current research is focused on integrated optics in AlGaAs.  Her two primary projects concern wavelength conversion by cross-phase modulation and four-wave mixing in AlGaAs waveguides and integrated pulse shaping devices.  Ksenia co-authored 13 papers in refereed journals, and gave 14 conference presentations.  She was awarded a prize for an outstanding student presentation at the Frontiers in Optics OSA Annual Meeting in Rochester in October 2008.