Imaging via spatial light modulation at photon-counting light levels

Abstract

Summary form only given. In summary when an incoming photon is absorbed by the avalanche photodiode (APD) under applied voltage, a localized avalanche of charge carriers is created. The electron avalanche causes localized heating, which alters the local optical properties (index of refraction) of the diode, allowing it to act as a spatial light modulator. Amplitude modulation may be easily achieved by using the front and backsurfaces of the APD to form a Fabry Perot interferometer. This thermo-optic modulation is observed even when a single photon initiates the response.