Examining the effectiveness of increasing EMCCD EM gain beyond standard manufacturer limits in determining photon...

Electron multiplying charge coupled device (EMCCD) cameras are widely used for single-photon detection in various quantum optics applications. For example, these EMCCD cameras have been extensively used to measure the position and momentum correlations between photon pairs produced by parametric down-conversion in the image and far-field planes of the down-conversion crystal, respectively. The camera's operating parameters are typically set to balance a high quantum efficiency while simultaneously maintaining a low number of erroneous photon detections, the latter being mainly attributable to clock-induced charge (CIC) events in the readout register. The visibility of the measured correlations is an indication of the quantum efficiency of detecting the photon pairs versus the prevalence of the unwanted CIC. In this work, we show that this correlation visibility can be enhanced by operating the EMCCD camera with the electron multiplying (EM) gain set well in excess of its standard operating conditions. This enhancement will be of interest to those using EMCCD detectors in quantum imaging, sensing and processing applications.