Various techniques are provided for performing detection using a focal plane array (FPA). For example, in one embodiment, a unit cell of an FPA may be implemented to support rapid sampling in response to one or more laser pulses reflected from an object or feature of interest. An FPA implemented with such unit cells may be used, for example, in an imaging system capable of detecting a plurality of two dimensional image frames and providing a three dimensional image using the detected two dimensional image frames. Other applications of such rapid sampling unit cells are also contemplated.