Influence of Background Illumination on the Photoresponse of Micropixel Avalanche

Micropixel avalanche photodiodes (MAPD) with deeply buried pixels have no structural components made on its front surface and therefore almost its entire surface is photosensitive. MAPD possesses high photodetection efficiency (PDE), multiplication gain ~105, photosensitivity from a single photon and wide range of dynamic linearity of photoresponse up to 5×103 photons/mm2. The influence of the background light on the gain and linearity of the photoresponse of the MAPD-3N type samples was investigated. External light sources have different effects on the output signal of MAPD whichever it is pulsed or continuous light. It is shown that in contrast to pulsed external light, the light from the permanent source leads to reducing of the output signal. But a constant background light does not deteriorate the linearity of the photoresponse in the whole range of linearity of the device.