Single-Photon Microcavity Structure for Wide-Band Light Collection

The patent merges multiple optical functions into a single integrated microcavity structure. The microcavity simultaneously provides light collection, resonance enhancement, and emission directionality control that would traditionally require separate components. This integration maintains high light collection efficiency while reducing structural complexity and manufacturing steps.

The microcavity structure serves multiple functions: it acts as a resonance cavity for enhancing light-matter interaction, as a collection lens for directing photons, and as an emission antenna for controlling radiation patterns. This multi-functionality allows a single structure to achieve high optical performance across different operational requirements.

The patent segments the quantum dot structure into distinct functional layers (active layer, barrier layers, contact layers) that can be independently optimized and manufactured. This segmentation allows each layer to be processed with standard techniques while maintaining precise relative positioning through epitaxial growth, reducing overall manufacturing precision requirements.

The quantum dots are pre-positioned and embedded within the semiconductor layers during epitaxial growth before final device assembly. This preliminary positioning ensures precise alignment is achieved during the growth process itself, eliminating the need for post-manufacturing alignment operations and reducing precision requirements for subsequent steps.

The patent achieves wide operating band by adjusting fundamental parameters of the microcavity structure: cavity depth, radius, and curvature. These geometric parameters directly control the resonance wavelengths and emission characteristics. By varying these parameters, the device can be tuned for different operating bands using standard fabrication techniques, avoiding the need for advanced materials.

The device uses composite semiconductor structures combining different materials (e.g., GaAs, AlGaAs) with complementary properties. This material composition enables broad spectral response and tunable emission characteristics while remaining compatible with established semiconductor fabrication processes, maintaining ease of manufacture.