Design of Fabry-Perot surface-emitting lasers with a periodic gain structure

A detailed analysis of a Fabry-Perot surface emitting laser (FP-SEL) which utilizes the recently proposed concept of periodic gain is presented. It is shown that by using the periodic gain concept, close to a factor-of-two reduction in threshold current should be possible; the ideal reduction of a factor of two is only limited by the internal loss of the cavity. Multiple quantum-well active regions are also considered and shown to provide greater than a factor-of-two improvement over bulk GaAs periodic and uniform gain configurations. The effects of index perturbations within the cavity created by interleaving active and passive segments are treated for different Al mole fractions within the passive segments. The effects are found to be small for x<0.3. In addition, optical pumping results in periodic gain DBR-SEL samples which exhibit very low optical power-density thresholds (<3×10⁴ W/cm²) and narrow above-threshold linewidths (<2 Å) are included