A multimode self-consistent model of the lasing characteristics of buried heterostructure lasers

Constricted mesa and buried heterostructure lasers have extremely wide modulation bandwidths due to their low parasitic capacitance and resistance and-because the structure provides very high confinement of both the carriers and photons in the active layer. The modulation bandwidth of these lasers is limited by current leakage effects and multilateral mode operation which both conspire to reduce the effective optical gain of the laser for a given operating current. These two problems are addressed and a fully self-consistent model of the lateral modal behavior and the current leakage problem in buried heterostructure lasers is addressed. The optical problem is solved using a modified version of the weighted index method, which provides a two-dimensional solution for optically active material with complex permittivity, and the onset of multimode behavior, where there is a superposition of two or more lateral modes, is also examined