Date and Time Wed, May 1st, 2013, 3:00 PM - 4:00 PM
Location Bahen Centre, Room 7180
Host Krishna Kishor

AlGaAs Nanowires: Optimal Conditions for Strong Optical Nonlinearity

Ksenia Dolgaleva

Aitchison Group, Photonics



Since the early days of the Nonlinear Optics, dating back to 1960s, nonlinear optical effects have gained a large number of applications, while still representing fundamental interest. It becomes especially crucial to integrate nonlinear optical devices on a chip to perform some optical signal processing functions. Among those are, for example, wavelength conversion and all-optical switching – the effects that fully rely on nonlinear optics. It is recognized by the researchers and industry in the field of optical communications that the next step towards all-optical networks of the future cannot be made without integrated nonlinear optical devices. Integrated nonlinear photonics is thus of crucial importance to information and communication technologies.

Aluminum gallium arsenide (AlGaAs) nanowires are high-index-contrast ultracompact waveguides with submicron dimensions. Due to the large index contrast (~ 0.15 between the claddings and guiding layer and ~ 3.5 between the guiding layer and the air surrounding the sidewalls of the nanowire) and small waveguide dimensions, AlGaAs nanowires have tiny modal areas. As a result, the optical power is highly concentrated in nanowires, which results in high intensities crucial for enhancement of the nonlinear optical interactions. In addition to the geometrical considerations contributing towards the efficiency of the nonlinear optical effects, AlGaAs is a highly nonlinear material with tailorable linear and nonlinear optical properties. All these facts make AlGaAs nanowires excellent devices for strong nonlinear optical interactions on a chip. In this talk, I will give an overview of the nonlinear optics in AlGaAs nanowires. I will cover the latest advances in this field and share our recent results on efficient tunable four-wave mixing in these structures.


Ksenia Dolgaleva earned her undergraduate degree in Physics from Moscow State University, Russia. She has completed her Ph.D. program at the Institute of Optics, University of Rochester, USA in 2009. There Ksenia 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 and others. Ksenia is currently finishing her postdoctoral fellow program at the Department of Electrical and Computer Engineering, University of Toronto, where she has been working with Prof. Stewart Aitchison. Her research at the University of Toronto has been focused on nonlinear integrated optics in AlGaAs. Ksenia has recently accepted an offer fron the University of Ottawa where she will become an Assistant Professor at the Canada Excellence Research Chair team lead by Prof. Robert Boyd. Her appointment at the University of Ottawa starts on July 1, 2013.