Cavity supermodes for gain‐saturated diode laser arrays

摘要

We present a numerical method for the solution of the cavity modes of a multichannel array of laser diodes. The analysis is based on coupled‐mode theory and includes the appropriate boundary conditions for the electric field at each reflecting facet. Saturable gain is also included, with saturation arising from both the forward‐going and reflected waves. We present results which differ from a recent analytic analysis for the case of two channels with different gains and propagation constants. The present work predicts ‘‘cavity supermodes’’ which are similar to the ‘‘symmetric’’ and ‘‘antisymmetric’’ waveguide supermodes previously described in the literature. These cavity modes are characterized by equal intensities in both channels even when the channel gains are grossly different.