New Observations of Group Delay in Multiphoton Processes
Scientists in Canada have made a groundbreaking advance in the field of quantum optics by observing group delay phenomena induced by gain during spontaneous parametric down-conversion (SPDC). In SPDC, a single high-energy photon is converted into two lower-energy “daughter” photons. Previous studies had largely focused on scenarios with a low probability of such photon conversions. However, by increasing the intensity of the pump laser, the researchers were able to generate multiple photon pairs simultaneously, ultimately revealing a measurable shift in the arrival times of the daughter photons.