Characteristics of Quantum Noise in Semiconductor Lasers Operating in Single Mode

The performance of a semiconductor laser is adversely affected by the presence of noise. A self-consistent numerical model is applied to analyze the intensity noise of 850 nm GaAs laser. A systematic technique has been demonstrated to introduce the Langevin noise sources on the photon number. The time varying profile of the fluctuating photon number and carrier number are analyzed. The frequency spectrum of the intensity noise is calculated with the help of Fast Fourier Transform (FFT). Transient behavior of semiconductor laser is also described that is significant in determining the noise characteristics of the laser output. In this paper, we aim to study the characteristics of quantum noise of semiconductor lasers operating in single mode since quantum noise is an intrinsic property of the semiconductor lasers and impossible to control in principle. The rate equations for photon numbers and carrier numbers for semiconductor laser operating in single mode are obtained by considering self-suppression coefficient. The parameters of the rate equations for GaAs are obtained and the noise effect is described through numerical simulation of the relative intensity noise (RIN). Photon number and carrier number variations with injection current are also demonstrated. Correspondence between this simulation results with practical data is also demonstrated