Spontaneous emission rate and phase diffusion in gain-switched laser diodes

Quantum random number generation (QRNG) has become a topic of growing interest in recent years due to important applications cryptography and simulations. Interferometric detection phase diffusion gain-switched single-mode semiconductor lasers is one the main techniques. In this paper, we study experimentally theoretically discrete mode laser diodes. We derive stochastic rate equations model for electric field that avoids numerical instabilities appear when simulating amplitude equations. Measurements are performed order extract parameters our laser. Spontaneous emission coupled into lasing measured as function carrier bias currents below threshold. A quadratic dependence obtained permits us evaluate validity linear approximations have been used describe QRNG. The good agreement between experiments theory give realistic quantitative description dynamical evolution statistics type QRNGs.