Fabrication of a nanophotonic quantum dot waveguide and photodetector integrated device

The authors present the design and fabrication of a nanophotonic waveguide and photodetector integrated device by molecular self-assembly of nanocrystal quantum dots (QD) and two different nano-gap formation techniques, namely electromigration-induced break-junction technique and electron beam lithography nano-gap patterning. A QD waveguide with ^50 nm width integrated with a nano-scale QD photodetector is achieved. A comparison is made between the two nano-gap techniques. In addition, a method to achieve high alignment accuracy for nanophotonic integration is discussed.