Role of p-doping profile in InGaAsP multi-quantum well lasers: Comparison of simulation and experiment

We study the role of p-doping on the characteristics of InGaAsP/InP multi-quantum well lasers through detailed simulations and experiments. The static and dynamic characteristics of a series of 1.3 mu m lasers with varying p-i junction placement were measured. The device characteristics were simulated including carrier transport, capture of carriers into the quantum wells, quantum mechanical calculation of the levels and optical gain in the wells and solution for the optical mode. The simulations were self consistent and carried out as a function of device bias. The simulations account for the trends observed with p-doping profile. In particular, the simulated optical gain and small signal resonance frequencies agree well with the measurements. The trend of larger resonance frequency with increased p-doping in the active layer of the laser depends on both the gain and the carrier transport through the multi-quantum well region.