This week's Colloquium in Physics & Astronomy

Imaging with undetected photons: infrared information, visible light Dr Emma Pearce University of Glasgow 15:00, Friday 3 July 2026 Physics Seminar Room (Building 46/5081) Infrared (IR) light reveals information that is inaccessible at visible wavelengths, providing access to chemical composition and material properties. As a result, IR imaging and sensing underpin a wide range of applications, from gas detection and biomedical microscopy to materials analysis and cultural heritage conservation. However, IR cameras remain expensive, noisy, and limited in resolution compared to their visible-wavelength counterparts. Imaging with undetected photons provides a route around this constraint by transferring information carried by infrared light to the visible, without ever detecting the infrared photons themselves. Non-degenerate photon pairs are generated in a nonlinear interferometer, where interference between photon pairs is recorded at visible wavelengths, with infrared transmission and phase imprinted onto the observed interference. In this talk, Dr Pearce will review recent experimental progress in this technique, including the development of practical, compact systems and emerging approaches to introduce new imaging modalities based on spatial control within the interferometer.

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