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PGI Colloquium: Prof. Dr. Daniele Faccio, University of Glasgow, UK

Online Talk

Please note: You will receive the link to the online talk in the e-mail invitation, usually sent out a few days before the lecture takes place. It is also available on request from the contact person below.

03 Dec 2021 11:00

Photon-number resolving quantum imaging

Quantum (optical) sensing techniques allow to measure properties of objects (phase profile, thickness, spatial distribution, absorption etc.) with a precision that is enhanced as a result of the exploitation of a quantum property of the states of light used to illuminate the sample. Commonly cited examples are N00N-state sensing that provides an N-times increase in measured phase shifts compared to a classical state of light at the same wavelength and squeezed-state sensing that provides sub-shot noise sensitivity.


More recent work as aimed at extending quantum sensing capability to the imaging domain, i.e. quantum state measurements distributed across an array of spatial points. The first attempts in this direction simply repeated a single-point sensing scheme and then scanned the `single point’ across the spatially distributed object, e.g. by scanning a collection fibre at the experiment output. We will discuss some recent work from our group in which we deploy recent advances in quantum imaging technology, namely the capability for cameras to directly measure the joint probability distribution of photon pairs across the whole sensor.

This technique, implemented on both emCCD and SPAD cameras, then allows for example to extend holography to measure object information encoded in the quantum phase of an entangled state or to spatially resolve photon bunching, i.e. Hong-Ou-Mandel interference, with micron-level precision. We will discuss the various techniques employed in our experiments together with the computational algorithms required to extract quantum phase information.

We will then discuss future directions and possibilities for these forms of quantum imaging based on photon number resolution on cameras.


David Edward Bruschi
Phone: +49 2461 61-6106