WP2 – Imaging with Timing

Work Package 2 – Imaging with Timing

How is a camera able to image light propagating in real time through the air? What camera is able to see around corners?

Work Package 2 – Imaging with timing, has answered these questions using single photon detection technologies to exploit the time correlation between source and detected return to provide range gated and 3D imaging functionality.

QuantIC’s “Light-in-Flight” and “Hidden Object Tracker” demonstrators (Gariepy, G et al, Nat.Photon. 10,23-26 (2016)) have been used to track a pulse of light propagating through a fibre and to track the position and speed of an object moving behind a solid wall. These cameras have individual photon counting pixels that allow us to capture extremely low light intensities (at the single photon level) and also obtain picosecond temporal precision, providing the ability to capture high speed action with an increase of over a million-fold frame rate when compared to the best commercial high speed cameras. It is the camera’s extreme sensitivity that enables it to detect the triple scattered light source of an object “around the corner”. This has led to an industry-led project in collaboration with Thales where the aim is to use the hidden object tracker technology to visualise objects inside a building and imaging through turbid media.

There is a very large market for cameras that are able to detect single photons with high temporal resolution, high quantum efficiency, and low noise performance. These cameras are important in applications such as fluorescence microscopy, quantum imaging, range finding, and low light level surveillance. The problem with current commercially available technologies is that no one camera has all the desired features at once: electron multiplying (EMCCD) cameras have a high quantum efficiency but relatively long exposures; intensified (ICCD) cameras provide very short exposure times and can be triggered at high repetition rates, but the efficiency of detecting single photons is very low. QuantIC’s Quantum State Imager (Dutton, N et al, Proc. Int. Image Sens. Workshop, Vaals,Netherlands, June 2015m pp. 170-173) is a camera based on single photon avalanche detector (SPAD) and aims to be a single camera system that will a viable alternative to the currently available EMCCDs and ICCDs. We are currently engaged with Lockheed Martin on testing the Quantum State Imager in a brown-out scenario.

QuantIC has also developed a quantum range finder, which will enable covert ranging using extremely low-light levels using a light source that emits two photons into two modes at exactly the same time. The development of the quantum range finder is reliant on the availability of the high-efficiency correlated photon pair “Q source” developed in Work Package 3.

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