Luminescence dating refers to a group of chronological dating methods of determining how long ago mineral grains were last exposed to sunlight or sufficient heating. It is useful to geologists and archaeologists who want to know when such an event occurred. It uses various methods to stimulate and measure luminescence. It includes techniques such as optically stimulated luminescence (OSL), infrared stimulated luminescence (IRSL), radiofluorescence (RF), infrared photoluminescence (IR-PL) and thermoluminescence dating (TL). "Optical dating" typically refers to OSL and IRSL, but not TL. The age range of luminescence dating methods extends from a few years to over one million years for red TL. Since the early applications of luminescence dating in the 1960/1970s, the field has received growing attention in the scientific community, with more than 3500 publications per year and >200 laboratories across the globe in 2020. Source: Wikipedia (en)