Mode reflectivity of narrow stripe-geometry double heterostructure lasers

The mode reflectivity of narrow stripe-geometry double heterostructure (DH) lasers is computed taking into account lateral (parallel to the junction) confinement in addition to transverse (normal to the junction) confinement. For most practical stripe width devices, the addition of lateral confinement insignificantly alters the reflectivity of the lowest order mode; calculations based upon transverse confinement alone (broad-area lasers) are analytically and numerically shown to provide an adequate description of the mirror reflectivities of most narrow stripe-geometry lasers.