Operating conventional electronic devices in the noninstantaneous multiplication (amplification) regime

Abstract

One requirement for operating a device in the noninstantaneous multiplication mode is that its response to an incident photon is the generation of a pulse of constant current. This current is allowed to have a fluctuating duration and can exhibit full shot noise. It is shown that a majority of conventional current-to-current and voltage-to-current converting devices should be operable in the noninstantaneous mode. Ideal photoconductive detectors (current-to-current converters) operated in the conventional (temporally deterministic) mode are a factor of 2 below the ideal limit on the signal-to-noise ratio set by the shot noise of the input light signal. When operated in the noninstantaneous mode these devices can be made to approach this ideal limit. The issue of resettability, i.e., the guaranteed turn off of each pulse of constant current, is examined with the help of a specific detector structure. Junction field-effect transistors are presented as an example of voltage-to-current converting devices operated in the noninstantaneous mode. The consequent improvement in the noise performance is also quantified.