Biophotonics and its Applications

Join Photons Canada and guest speakers Dr. David Lindell and Dr. Andrew Kirk for a discussion of biophotonics and its applications.

Speakers

Andrew Kirk – Professor, Department of Electrical and Computer Engineering, McGill University

Andrew Kirk is a professor in the Department of Electrical and Computer Engineering at McGill University. His research interests include optical biosensors for point of care medical diagnostics and environmental sensing, and integrated and nanophotonic devices for sensing and communications. He leads the Photonic Biosensors group, which develops low cost and rapid solutions for healthcare and the environment.

David Lindell – Assistant Professor, Department of Computer Science, University of Toronto

David Lindell is an assistant professor in the Department of Computer Science at the University of Toronto. His research combines optics, emerging sensor platforms, machine learning, and physics-based algorithms to enable new capabilities in visual computing. His research has a wide array of applications including autonomous navigation, virtual and augmented reality, and remote sensing.

Abstracts

Andrew Kirk: “How can photonics accelerate the diagnosis of infectious diseases?”

The covid19 pandemic has made evident the essential role that diagnostic tests based on the polymerase chain reaction (PCR) can play in infection control. Based on the selective amplification of nucleic acids, PCR is able to detect the presence of a very low concentration of specific DNA or RNA molecules (down to single molecules in some cases). Since its invention 40 years ago, PCR has become the standard diagnostic procedure for a wide variety of infections, and also finds application in many other fields such as agriculture, forensic science, forestry and environmental health. The PCR amplification process requires that the sample under test be thermocycled between the DNA annealing temperature (around 55°C) and melting temperature (around 95°C) 30-40 times. Conventional PCR thermocyclers make use of thermoelectric heaters and coolers to accomplish this, and as a result are often bulky and have a high power consumption. Typically they require at least 30 minutes (and up to one hour) to deliver a result. Recently there have been a number of innovations in methods to reduce the time to result, and also to decrease the bulk, cost and power requirements of PCR thermocyclers. Often the objective of these innovations is to transform PCR into a point-of-care (POC) diagnostic tool. This talk will describe some of these approaches, with a particular focus on thermocycling using laser heating of plasmonic nanoparticles or films, but also considering other aspects including microfluidics and biological factors. It will also highlight some of the significant challenges that remain in translating PCR to the POC arena.

David Lindell: “Passive ultra-wideband single-photon imaging”

For the majority of computer vision algorithms and camera systems, an image can be modeled as sampling a continuous function representing the time-varying intensity of light incident on each pixel. However, in extreme imaging scenarios, such as imaging at high speeds or in near-total darkness, this conventional model breaks down. In this regime—at the photon limit—imaging is an inherently discrete process based on photons that arrive individually, stochastically, and asynchronously. In this talk, I describe a theory that bridges measurements of discrete photon arrival times with a model of continuous time-varying intensity assumed by most imaging systems. Surprisingly, a continuous reconstruction of incident flux is possible even if it varies orders of magnitude faster than the timespan between consecutive photon arrivals. Applying this theory experimentally to photon arrivals captured using single-photon avalanche diodes enables recording ultra-wideband video, which can be played back later at 30Hz to show everyday motions—but can also be played a billion times slower to show the propagation of light itself.

When

August 23, 2023
1:30pm – 3:00pm EDT
Via Zoom

Free for Photons Canada members/ $30 for nonmembers

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