Quantum noise of diode laser radiation

Abstract

Abstract Semiconductors lasers from several manufacturers have been investigated. Rate equations were proposed to describe the dynamics and explain the mechanisms of the appearance of quantum noise in diode lasers. Stationary solutions of the rate equations were obtained. For the lasers under study, the threshold currents and the number of photons at the threshold are obtained. Four mechanisms of the quantum noises appearance were described: Poisson noises of the photons, Poisson noises of the electrons, shot noises of the pump current, and quantum noise of the radiation field. The photon lifetimes for the investigated diode lasers have been determined. The shot noise of the pumping current does not play a significant role. The Poisson noise of photons is responsible for the maximum noise at the generation threshold of a diode laser. The analysis of quantum noises of quantum-cascade diode lasers is carried out.