Abstract
The application of analog/digital converters and inverse techniques for optical receiving by photon detectors, when their output single pulses are strongly overlapped, is described. It is shown that the counting of overlapped pulses can be realized by a set of linear transformations—conversion of single pulses into decayed oscillations, digitizing, averaging, Fourier deconvolution, normalizing, and digital filtering. This method does not use discriminators, being insensitive to the pulse shape. The theoretical analysis is supported by computer simulations and experimental data. It is shown that photon statistics can be saved into the retrieved optical profiles at mean counting rates exceeding 1 GHz. The retrieving error is not higher than Poisson fluctuations. This method is effective simultaneously in the both typical regimes of photon detectors—photon counting and overlapping. It can be applied in lidar remote sensing, time-resolved spectroscopy, etc.
