Single photon detector on avalanche photodiode

Amplification pulse signals a single-photon detector based on an avalanche photodiode

“…If the total number of pulses at the output of the photodetector is N, then only N1 pulses will exceed the specified threshold of amplitude discrimination. Then the probability of exceeding the threshold can be determined by the ratio N1 / N [13][14][15][16] . By controlling this ratio, it is possible to conclude that the value of U has changed.…”

A method of quantum communication using sideband-modulated infrared emission

“…Its distinctive feature is to move the quantum channel to the side frequencies generated as a result of modulation. This ensures high resistance to influence of external factors and spectral efficiency, as well as good indicators in terms of the ratio of the speed of key formation to the distance between sender and receiver blocks 11,12 . However, as part of such type of systems for short and medium distances, single photon detectors based on APD are also used, and resistance to attacks on the measuring equipment of quantum communication systems at side frequencies has not been studied.…”

“…The method was developed by several groups in different practically significant directions. The increase in spectral efficiency due to the formation of several side frequencies simultaneously 11,12 . Methods, solutions and approaches were developed to increase tactical and technical characteristics of quantum communication systems 9,10 .…”