Angle-insensitive spectral imaging based on topology-optimized plasmonic metasurfaces

TL;DR

This paper introduces a novel angle-insensitive spectral imaging method using topology-optimized plasmonic metasurfaces, enabling robust on-chip spectral reconstruction across a wide field-of-view with high fidelity.

Contribution

The work presents a new design for angle-robust spectral recovery using topology-optimized metasurfaces, overcoming angle sensitivity limitations in spectral imaging devices.

Findings

Achieved angle-insensitive spectral imaging from 450 to 750 nm.

Demonstrated spectral reconstruction fidelity of 98%.

Validated the design through experimental fabrication and testing.

Abstract

On-chip spectral imaging based on engineered spectral modulation and computational spectral reconstruction provides a promising scheme for portable spectral cameras. However, the angle dependence of modulation units results in the angle sensitivity of spectral imaging, which limits its practical applications. Here, we proposed a design for angle-robust spectral recovery based on a group of topology-optimized plasmonic metasurface units under a 30{\deg} field-of-view, and demonstrate angle-insensitive on-chip spectral imaging in the wavelength range of 450 to 750 nm for average polarization. Furthermore, we experimentally verified the angle-insensitive spectral filtering effects of the fabricated metasurface units, and demonstrated angle-robust spectral reconstruction with a fidelity of 98%. Our approach expands the application scale of spectral imaging, and provides a guidance for designing other angle-robust devices.