Ultra-compact on-chip reconstructive spectrometer based on cascaded microrings and waveguide Bragg gratings

The growing demand for the portability of spectral detection systems is driving continuous breakthroughs in the development of spectrometers towards on-chip integration. In this process, the ultra-compact design of spectrometers is not only a necessary condition for achieving their compatibility with mobile devices and Internet of Things terminals, but also a core prerequisite for promoting the technology towards broader application scenarios. Although traditional spectrometers can achieve high resolution, the bulky and discrete component layouts make them incompatible with the requirement for ultra-high integration, which means significant trade-offs between the footprint and performance. To address this contradiction, this paper proposes a computationally reconstructed on-chip spectrometer based on synchronously tuned micro-ring resonators and waveguide bragg grating. Within an ultra-small chip area of 8 μm × 100 μm, the device is expected to achieve an average resolution of 0.17 nm and a bandwidth coverage of 60 nm, with a spectral channel density more than 440000 ch/mm2. This provides a competitive solution for spectral analysis modules in highdensity integrated optical systems.