Effect of mode nonorthogonality in distributed-feedback lasers.

An analysis of the quantum noise in distributed-feedback lasers based on the Fokker-Planck equation has been developed to take into account the nonorthogonal nature of the laser modes. We have obtained numerical results of the steady-state solution of the single-mode operation that reveal the difference between the standard approach orthogonal laser modes and the realistic model (mode nonorthogonality included) for a distributed-feedback laser with nonvanishing end reflectivity and the complex coupling coefficient.