Optically stimulated luminescence (OSL) and radio photoluminescence (RPL) are methods used for measuring doses from ionizing radiation. In typical arrangements, a device or material is optically stimulated and then emits luminescence (photons) as a result of the optical stimulation that is proportional to the ionizing radiation dose. Photons are detected using a sensitive light detector, such as a photomultiplier tube, and the signal from the detector is then used to calculate the dose that the material has absorbed. Maximizing the signal-to-noise ratio of the optical measurements is one of the main challenges in luminescence dosimetry. The major difficulty with achieving very high signal-to-noise ratios at the extremely low ionizing radiation doses, which is required for modern personnel dosimetry, is the ability to minimize and ultimately reject background signals that are not related to the luminescence emission that is proportional to the ionizing radiation exposure.

To address this challenge, PNNL scientists have developed a method of measuring luminescence of a material by applying a light source to excite an exposed material. The method amplifies an emission signal of the material and measures the luminescent emission at a fixed-time window of about 10 picoseconds to about 10 nanoseconds. The method measures the luminescence of a material, reduces the background fluorescence of a material, and the properties of a luminescent material.