Waveguiding in vertical cavity quantum-well structure defined by ion implantation

A theoretical model is presented for investigating AlGaAs-GaAs quantum-well (QW) vertical cavity waveguides defined by impurity-induced disordering. This model is based on a two-dimensional (2-D) description of the implantation profile to produce quantum-well intermixing. The modal propagation constant, power, and field evolution along the nonuniform circular waveguide is analyzed in terms of the coupled-mode equation. The influence of varying the mask dimension and length of cavity on the fundamental mode operation is studied. In a long cavity, guided mode can be supported by using higher implantation energy, however, a larger mask diameter should be used to maintain strong guiding. Result shows that optical lateral confinement is accomplished, with more than 70% of the power gathered in the cavity. The fraction of power confined in the waveguide is shown to improve by 30% after annealing. In addition, waveguide loss is estimated to be less than 40 cm^-1 which results in less than 1 dB for our structure