Truly random number generation via entropy amplification

We present a simple setup to implement truly random number generator based on the measurement of the laser phase noise. From the entropy point of view, we estimate the number of truly random bits that can be extracted from the sampled Byte. With a simple method of adopting the $m$-least-significant-bit, we amplify the entropy of the original bit sequence and realize a truly random bit generation rate of $300$ Mbps.