A radiation detection device integrates the number of optical photons in a light pulse. The radiation detection device includes an optical detector pixel array which has a plurality of pixel cells that are triggered by optical photons, a plurality of pixel cell trigger state sensing circuits, and a summing unit. Each pixel cell trigger state sensing circuit generates a digital signal having either a first predetermined amplitude indicative of a triggered pixel cell, or a second predetermined amplitude indicative of a non-triggered pixel cell. The summing unit generates an analog signal whose amplitude corresponds to the number of triggered pixel cells and thereby performs the integration. The analog signal may further cause a timing unit to generate a timestamp when a predetermined accumulated optical photon count condition is met.
