  In this study, a compact and low-power-consumption quantum random number
generator (QRNG) based on a laser diode and silicon photonics integrated hybrid
chip is proposed and verified experimentally. The hybrid chip's size is
8.8*2.6*1 mm3, and the power of entropy source is 80 mW. A common mode
rejection ratio greater than 40 dB was achieved using an optimized 1*2
multimode interferometer structure. A method for optimizing the
quantum-to-classical noise ratio is presented. A quantum-to-classical noise
ratio of approximately 9 dB was achieved when the photoelectron current is 1
microampere using a balance homodyne detector with a high dark current GeSi
photodiode. The proposed QRNG has the potential for use in scenarios of
moderate MHz random number generation speed, with low power, small volume, and
low cost prioritized.
