Angle-resolved miniature spectrometer using CMOS-compatible metasurface Fabry-Pérot filters and compressive sensing

Area of Science:

• Optics and Photonics
• Nanotechnology
• Spectroscopy

Background:

• Miniaturized spectrometers are crucial for portable sensing.
• Metasurface filters face performance degradation with increasing illumination angles.
• Existing designs lack simultaneous spectral and angular information retrieval.

Purpose of the Study:

• To develop a multiplexed metasurface architecture for simultaneous spectral reconstruction and angle of incidence determination.
• To overcome the angular sensitivity limitations of current metasurface spectrometers.
• To enable compact spectrometers for applications requiring both spectral and geometric information.

Main Methods:

• Designed a CMOS-compatible multiplexed metasurface combining high-Q and medium-Q Fabry-Pérot filters.
• Utilized a self-adaptive reconstruction algorithm for data processing.
• Integrated two filter types with complementary angular responses.

Main Results:

• Achieved accurate retrieval of chlorophyll-a fluorescence spectra with a low RMS error (6.9 × 10^-3).
• Determined illumination angles with high accuracy (within 1°).
• Demonstrated simultaneous spectral and angular measurement capabilities.

Conclusions:

• The proposed multiplexed metasurface architecture offers a practical solution for compact spectrometers.
• This technology enhances portable sensing by providing both spectral and illumination geometry data.
• Opens new avenues for applications in agriculture, geology, and industrial monitoring.