Effect of photon statistics on vacuum fluctuations based QRNG

Abstract

The speed of quantum random number generators (QRNGs) is a major concern for practical applications. In this work, we introduce scattering as a method to enhance the randomness characteristics of the entropy source. This method allows optical bit extraction with a faster sampling rate without compromising the randomness quality compared to the coherent source based balanced homodyne detection. Scattering is a probabilistic phenomenon which increases the chaotic behaviour of coherent sources. It broadens the distribution of photon statistics and makes it super-Poissonian. We show that a signal with super-Poissonian distribution has better randomness compared to a Poissonian one, indicated by their autocorrelation characteristics and the randomness test results. The use of scattering mechanisms as an entropy source eases the miniaturization of QRNGs, it also makes them compatible and adaptable to existing technologies.