Spectral encoding based on narrowband/broadband modulations of QBIC for computational spectral imaging

Area of Science:

• Nanophotonics
• Computational Imaging
• Spectroscopy

Background:

• Accurate spectral reconstruction in computational imaging relies on nanophotonic encoder modulations.
• Conventional encoders struggle with narrowband spectral features due to trade-offs between wavelength range, light efficiency, and spectral resolution.

Purpose of the Study:

• To propose a simultaneous narrowband and broadband spectral encoder using quasi-bound states in the continuum (QBIC).
• To overcome the limitations of conventional nanophotonic encoders for high-accuracy spectral imaging.

Main Methods:

• Designed a QBIC structure with tunable resonances by scaling lateral dimensions.
• Integrated broadband transmittance modulation with QBIC resonances for combined spectral modulation.
• Evaluated performance against multilayer film modulators in real-world scenarios.

Main Results:

• Achieved simultaneous narrowband and broadband spectral modulation.
• Enhanced average peak signal-to-noise ratio by 5.33 dB.
• Reduced full width at half maximum error by approximately 5 nm compared to conventional modulators.

Conclusions:

• The proposed QBIC-based encoder overcomes resolution limitations of conventional modulators.
• This approach enables high-accuracy and miniaturized computational imaging systems.
• Offers new possibilities for advanced spectral encoding in nanophotonics.