Subdiffraction Photon Guidance by Quantum-Dot Cascades

Abstract
We report on a waveguide composed of a cascade of gain-enabled quantum dots with subwavelength dimensions. Fabrication is demonstrated through DNA-mediated self-assembly and a two-layer molecular self-assembly process that enables rapid prototyping. The device, which is identified with fluorescence microscopy and tested by optical near field detection, allows optical signal transfer at a well-defined wavelength in flexible routing geometry, such as straight paths and 90° bends. The structure serves as a critical building block for nanophotonic systems with high integration density.