Time-correlated single photon counting

Time-correlated single photon counting (TCSPC) is a way of measuring light. It can measure both the intensity, which is how bright the light is, and the time, which is how long it takes for the light to travel from one place to another. In TCSPC, the light is split into individual photons, which are tiny particles of light. Each photon travels in a separate direction, and when it reaches a detector, the detector measures how long it took and how bright it was. This information is then used to understand and measure the light.