An inversely designed integrated spectrometer with reconfigurable performance and ultra-low power consumption

Despite the pressing demand for integrated spectrometers, a solution that deliver high-performance while being practically operated is still missing. Furthermore, current integrated spectrometers lack reconfigurability in their performance, which is highly desirable for dynamic working scenarios. This study presents a viable solution by demonstrating a user-friendly, reconfigurable spectrometer on silicon. At the core of this innovative spectrometer is a programmable photonic circuit capable of exhibiting diverse spectral responses, which can be significantly adjusted using on-chip phase shifters. The distinguishing feature of our spectrometer lies in its inverse design approach, facilitating effortless control and efficient manipulation of the programmable circuit. By eliminating the need for intricate configuration, our design reduces power consumption and mitigates control complexity. Additionally, our reconfigurable spectrometer offers two distinct operating conditions. In the Ultra-High-Performance mode, it is activated by multiple phase-shifters and achieves exceptional spectral resolution in the picometer scale while maintaining broad bandwidth. On the other hand, the Ease-of-Use mode further simplifies the control logic and reduces power consumption by actuating a single-phase shifter. Although this mode provides a slightly degraded spectral resolution of approximately 0.3 nm, it prioritizes ease of use and is well-suited for applications where ultra-fine spectral reconstruction is not a primary requirement.