  We demonstrate a quantum random number generator based on the random nature
of the phase difference between two independent laser sources. The speed of
random bit generation is determined by the photodetector bandwidth and the
linewidth of the lasers used. The system implemented is robust and generates a
probability distribution of quantum origin which is intrinsically uniform and
thus in principle needs no randomness extraction. The phase is measured with
telecom equipment routinely used for high capacity coherent optical
communications, which allows to keep track of the phase drift of the lasers and
is readily available in the telecommunication industry.
