Fig. 2: Spectrometer design and simulations.
a Conceptual Schematic of the proposed ultra-broadband spectrometer featuring multiple stages of micro-ring resonators on a single bus. The inset shows the mode field distribution on the bus waveguide. b Structural diagram of a dispersion engineered ring resonators with a curved directional coupler. c Calculated values of \({T}_{{res}}\) under different combinations of \(\alpha\) and \(r\). The insets highlight the target region of \(\alpha\) and \(r\) for the micro-ring resonators. d Simulated coupling efficiency of the optimized curved directional coupler, showing an increasing cross-coupling efficiency over wavelength to match the rising round-trip loss on the ring. e Simulated light propagation profiles in the curved directional coupler at different wavelengths, shown as normalized electric field intensities. f Simulated spectral response for one of the cascaded ring resonators, showing the targeted over coupling state across an ultra-wide wavelength range.
