Coupling coefficients for distributed feedback single- and double-heterostructure diode lasers

We compute coupling coefficients for TE modes as a function of tooth height, active layer thickness, and Bragg scattering order in single-heterostructure (SH) and double-hetetostructute (DH) distributed feedback (DFB) diode lasers for a variety of corrugation shapes. In particular, equations for rectangular, sinusoidal, and triangular shapes are evaluated; the last both in the symmetric and saw-tooth cases. It is shown that the coupling coefficient for rectangular and sawtooth gratings decreases much less rapidly with increasing Bragg order than do the sinusoidal and symmetric triangular.