Ultra-high speed random bit generation based on Rayleigh feedback assisted ytterbium-doped random fiber laser

In this paper, we propose an ultra-high speed random bit generator without the time-delay signature based on an ytterbium-doped random fiber laser (YRFL) with Rayleigh scattering feedback. The spectrum of the YRFL has a relatively broad bandwidth (0.35 nm) and the lasing temporal intensity shows random fluctuations without cavity induced time-delay signatures (TDS), which are essential for ultra-high speed random bit generation The chaotic signal and its time-delayed signal sampling at 40 Giga samples per second (GS/s) are converted to digital 8-bit signals. By selecting 5 least significant bits from each 8-bit digital signal and using bitwise exclusive-OR operation, we experimentally achieve 200 Gbps physical random bit generation based on ytterbium-doped random fiber laser with the verified randomness. The combination of broadband emission and free of TDS makes random fiber lasers new promising sources for high performance random bit generation in a simple and compact configuration, which has a great potential in cryptography and secure communication applications.