Interdiffused quantum nanostructure for photonics integration

The effect of quantum nanostructure interdiffusion or intermixing using impurity free vacancy diffusion (IFVD) and impurity induced disordering (IID) techniques, on the various types of GaAs- and InP-based quantum-well (QW) and quantum-dot (QD) structures for postgrowth photonic device integration is presented Using IFVD, we have demonstrated the fabrication of photonic integrated circuits such as multi-wavelength laser chips and broadband superluminescent diodes in GaAs/AlGaAs QW structures. Postgrowth bandgap engineering using low energy neutral ion implantation technique has been developed in InGaAs/InGaAsP QW systems. Using this interdiffusion technique, 10-channel multi-wavelength lasers and 8-channel integrated optical performance monitors have been demonstrated. The effects of IFVD and IID on the interdiffusion of InGaAs/GaAs QDs have been investigated. High spatial bandgap selectively processes with differential bandgap shifts between the interdiffused and non-interdiffused sections of over 100 meV have been observed from both IFVD and IID techniques in InGaAs/GaAs QD laser structure. At theoretical modeling level, we have developed a unified three-dimensional model for the electronic states calculation of the interdiffused quantum nanostructures with arbitrary shape, which is universally applicable to various quantum structures such as QW, quantum wire, quantum dash, and QDs. This model serves as a valuable tool to gain a more physical understanding of interdiffusion or intermixing techniques suitable for the integration technology in quantum nanostructures.