Effect of photon recycling in pixelless imaging device

We present an analytical model for the photon recycling effect associated w ith the reabsorption of generated photons in a light-emitting diode (LED) d riven by nonuniform current injected from a quantum well infrared photodete ctor (QWIP), The model is applied to the evaluation of the modulation trans fer function and the external quantum efficiency in pixelless imaging devic es based on the integration of a QWIP with a LED. The modulation transfer f unction and the signal external quantum efficiency of a QWIP-LED pixelless imager are calculated as functions of the structural physical and geometric al parameters. It is shown that photon recycling is a significant factor th at limits the spatial resolution of images and increases the external quant um efficiency.