Nonlinear characterization of modal gain and effective index saturation in channeled-substrate-planar double-heterojunction lasers

The nonlinear modal gain and effective index in AlGaAs/GaAs channel-substrate-planar double-heterojunction (CSP-DH) lasers are calculated as a function of the drive current and intracavity power. These functions are first computed using a self-consistent procedure that ties together the optical fields and the carrier distribution in the active layer. The functions are then suitably fit to a new empirical analytic expression that is useful for modeling the laser as a single device or as multiple lasers that are coherently locked. The specific analytic expressions are simple algebraic formulas that have six parameters that can be calculated using regression techniques. These parameters are computed for the CSP-DH laser as a function of the stripe contact width