Analysis for Dynamic Characteristics and Relative Intensity Noise of a New Polarization-Insensitive Quantum Well Structure Optoelectronic Integrated Device

A polarization-insensitive optoelectronic integrated device composed of a tensile strained periodic coupled double quantum wells heterojunction phototransistor integrated over a compressive strained multi quantum well laser diode (MQW-LD) is proposed. This structure shows unresolved heavy hole and light hole transitions. So, the device operation mode (amplification or switching) is independent of input light polarization. A rigorous numerical analysis for dynamic response and relative intensity noise of the device is presented. The model is based on device rate equations, for which we require to calculate the MQW-LD gain and phototransistor electroabsorption coefficient. The Hamiltonian of strained QW structure is numerically solved by transfer matrix method taking into account the band mixing between heavy hole and light hole. In order to calculate the electroabsorption coefficient, the exciton equation is solved numerically in momentum space using Gaussian quadrature method. Langevin noise sources in laser part, phototransistor current noise, input power noise and noise due to the internal optical feedback from laser to phototransistor are considered as the device noise sources