Signal acquisition via polarization modulation in single photon sources

TL;DR

This paper introduces a model for using polarization modulation in single photon sources to transduce analog information, analyzing the quantum noise effects and information capacity of the system as a noisy optical communication channel.

Contribution

It presents a theoretical scheme for analog information transduction using polarization modulation in single photon sources, incorporating quantum noise and binomial photon statistics.

Findings

Classical information capacity increases logarithmically with the square root of photon number N.

Quantum noise due to polarization detection limits the information transmission per sample.

Capacity remains logarithmically increasing even with detector non-idealities.

Abstract

A simple model system is introduced for demonstrating how a single photon source might be used to transduce classical analog information. The theoretical scheme results in measurements of analog source samples that are (i) quantized in the sense of analog-to-digital conversion and (ii) corrupted by random noise that is solely due to the quantum uncertainty in detecting the polarization state of each photon. This noise is unavoidable if more than one bit per sample is to be transmitted, and we show how it may be exploited in a manner inspired by suprathreshold stochastic resonance. The system is analyzed information theoretically, as it can be modeled as a noisy optical communication channel, although unlike classical Poisson channels, the detector's photon statistics are binomial. Previous results on binomial channels are adapted to demonstrate numerically that the classical information capacity, and thus the accuracy of the transduction, increases logarithmically with the square root of the number of photons, N. Although the capacity is shown to be reduced when an additional detector nonideality is present, the logarithmic increase with N remains.