High-Speed and Bias-Free Optical Random Number Generator

True randomness is critical to secure communication in both quantum and classical regimes. We propose an approach of true random number generation based on the intrinsic randomness of spontaneous emission. In this approach, a method of random bit extraction was employed to extract true random bits simultaneously as the measurement of the physical entropy source. The random bits generated by the true random number generators have been statistically verified to be bias-free and mutually independent. With the current experimental setup, 7 random bits can be generated in parallel at a rate up to 40 GHz.