Vertically Stacked Slab Waveguide SHS for Spectral Resolution

The patent transitions from conventional 2D grating-based spectrometers to a 3D integrated photonic circuit architecture where multiple waveguide layers are stacked vertically. This vertical stacking enables high spectral resolution through precise optical path difference control in the depth dimension while maintaining large étendue through parallel processing of multiple spectral channels across different layers, thereby resolving the contradiction between resolution and light gathering capability.

The spectrometer is segmented into multiple independent waveguide layers, each tuned to detect unique narrow spectral regions. Each layer functions as an independent spectral channel that can be processed simultaneously, allowing the system to achieve high overall resolution by combining results from multiple segments while maintaining large total étendue through parallel light collection across all layers.

The patent merges multiple waveguide layers into a single integrated photonic circuit structure where the relative positions and orientations of layers are fixed during fabrication. This consolidation eliminates the need for separate alignment procedures for each waveguide array, as the entire multi-layer structure is manufactured as one unit with predetermined geometric relationships, thereby achieving spectral dispersion while relaxing alignment tolerance requirements.

The patent replaces mechanical alignment procedures with integrated photonic circuit fabrication techniques. Instead of mechanically assembling and aligning separate waveguide arrays, the system uses semiconductor manufacturing processes to create precisely positioned waveguide layers in a single integrated structure, substituting mechanical alignment precision requirements with controllable fabrication tolerances.

The patent replaces the mechanical moving mirror of traditional Fourier Transform Spectrometers with a static integrated photonic circuit structure. The optical path difference variation traditionally achieved by mechanical mirror displacement is instead accomplished through fixed waveguide path length differences embedded in the photonic circuit geometry, eliminating moving parts while maintaining high spectral resolution through the interferometric principle.

The patent merges the interferometer function with the waveguide structure itself, creating an integrated photonic circuit where the waveguides serve dual purposes as both light transmission paths and interferometric elements. This consolidation eliminates separate moving components by embedding the interference function directly into the static waveguide geometry, achieving high resolution without mechanical complexity.