40 Gb/s quantum random number generation based on optically sampled amplified spontaneous emission

We present a photonic approach for fast quantum random number generation based on optically sampled amplified spontaneous emission (ASE). This utilizes terahertz optical asymmetric demultiplexer to sample the ASE and then digitize pulses into bits using multi-bit parallel comparator. A proof-of-concept experiment demonstrates that 40 Gb/s with verified randomness can be obtained our method. The current rate is mainly limited by bandwidth of available source.