Analysis of gain-guided modes in active semiconductor waveguides

The complex reduced width of an active semiconductor waveguide is introduced as a parameter of waveguides with symmetric and asymmetric refractive index profiles in the p–n junction plane (Epstein layer model). The parameters of the angular distribution diagrams of the radiation emitted by such waveguides are plotted as a function of the real and imaginary parts of the complex reduced width. The coupling coefficients of the modes are obtained in a model describing a heterolaser, inhomogeneous along its length formed by two (or more) active waveguides in contact. A comparison is made with the output characteristics of planar stripe heterolasers without lateral optical confinement.