Towards Integrating True Random Number Generation in Coherent Optical Transceivers


Towards Integrating True Random Number Generation in Coherent Optical Transceivers


Dinka Milovančev, Nemanja Vokić, Christoph Pacher, Imran Khan, Christoph Marquardt, Winfried Boxleitner, Hannes Hübel, and Bernhard Schrenk.


The integration of quantum communication functions often requires dedicated opto-electronic components that do not bode well with the technology roadmaps of telecom systems. We investigate the capability of commercial coherent transceiver sub-systems to support quantum random number generation next to classical data transmission, and demonstrate how the quantum entropy source based on vacuum fluctuations can be potentially converted into a true random number generator for this purpose. We discuss two possible implementations, building on a receiver- and a transmitter-centric architecture. In the first scheme, balanced homodyne broadband detection in a coherent intradyne receiver is exploited to measure the vacuum state at the input of a 90-degree hybrid. In our proof-ofprinciple demonstration, a clearance of >2 dB between optical and electrical noise is obtained over a wide bandwidth of more than 11 GHz. In the second scheme, we propose and evaluate the re-use of monitoring photodiodes of a polarization-multiplexed inphase/quadrature modulator for the same purpose. Time-interleaved random number generation is demonstrated for 10 Gbaud polarizationmultiplexed quadrature phase shift keyed data transmission. The availability of detailed models will allow to calculate the extractable entropy and we accordingly show randomness extraction for our two proof-of-principle experiments, employing a two-universal strong extractor.


IEEE Journal of Selected Topics in Quantum Electronics (JSTQE), vol. 26, no. 5, p. 6400608, Sep. 2020