Researchers at the University of Toronto have figured out a way to “nudge” nature into making photonic crystals in a specific order and pattern, a critical first step in the development of photonic circuits and microchips.

Photonic crystals allow scientists to control the flow of light. Light can carry much more information than current electronic switches and Internet routers, says Professor Ted Sargent of the electrical and computer engineering department. But light is difficult to control. While scientists have been successful in creating a stable photonic crystal, they have not been able to control its placement and degree of order and configuration on the surface of materials up until now, a crucial factor when it comes to building things like circuitry.

“The photonic integrated circuit is the holy grail of the optical communications industry,” Sargent says. “Our work with these crystals established one of the first steps necessary to one day creating a photonic microchip.”

The team’s research involved growing colloidal crystals – also known as artificial opals – on textured surfaces. This process allowed them to precisely control the placement and ordering of the crystals into desired patterns. Sargent conducted the research with U of T chemistry professor Eugenia Kumacheva and two graduate students. Their work appeared in the Feb. 15 issue of Advanced Materials.

Sargent likens their process to that of an orchestra’s conductor who does not play all the instruments or notes, but rather sets the rhythm and placement. “Nature is still doing all the work in creating photonic crystals; we’re just politely asking it to do it in a particular location with a defined order and configuration.”


CONTACT: Professor Ted Sargent, Department of Electrical and Computer Engineering, 416-946-5051, or Janet Wong, U of T public affairs, 416-978-5949,