Figure 2: Data processing.
(a) To process the acquired data, we first subtract a background acquired by the SPAD camera without the laser beam propagating across its field of view. It allows us to see the path, but the image (b) is still very noisy. (c) To get a clearer image, we fit a Gaussian to every histogram. If the Gaussian is much wider than we expect, or smaller than the pulse duration, we set the histogram to zero. (d) We then deconvolve the fitted Gaussians down to a 500-ps Gaussian (e). (f) Finally, to improve the resolution of our frames, we interpolate between the centre of mass of two adjacent lines/columns.
