Snapshot spectral imaging with parallel metasystems

Abstract

Spectral imagers divide scenes into quantitative and narrowband spectral channels. They have become important metrological tools in many areas of science, especially remote sensing. Here, we propose and experimentally demonstrate a snapshot spectral imager using a parallel optical processing paradigm based on arrays of metasystems. Our multi-aperture spectral imager weighs less than 20 mg and simultaneously acquires 20 image channels across the 795- to 980-nm spectral region. Each channel is formed by a metasurface-tuned filter and a metalens doublet. The doublets incorporate absorptive field stops, reducing cross-talk between image channels. We demonstrate our instrument’s capabilities with both still images and video. Narrowband filtering, necessary for the device’s operation, also mitigates chromatic aberration, a common problem in metasurface imagers. Similar instruments operating at visible wavelengths hold promise as compact, aberration-free color cameras. Parallel optical processing using metasystem arrays enables novel, compact instruments for scientific studies and consumer electronics.

Inverse design enables large-scale high-performance meta-optics reshaping virtual reality

“…Recent breakthroughs in the physics 7 – 11 and advancements in large-scale meta-optics fabrication 12 – 14 inspire a vision for a future in which meta-optics will be widely used. Recent studies have demonstrated cutting-edge technologies based on meta-optics platforms, such as polarization/light-field/depth imaging cameras 15 – 18 , metasurface-driven OLEDs 19 , virtual/augmented reality systems 20 , 21 , compact spectrometers 22 – 24 , etc. So far, the mainstream design of the meta-optics is mostly based on a “forward” methodology, in which one engineers each individual meta-atom component (as a phase shifter) independently, according to a predefined phase profile 25 , 26 .…”

Integrated photonic metasystem for image classifications at telecommunication wavelength

“…Metasurface-based multi-layer systems, named metasystem, expand the functionality of metasurface in the out-of-plane dimension 38 – 40 . Lithographically assisted alignment and bonding between metasurface layers are required for providing sufficient precision and robustness in functional metasystems 39 , 40 .…”

Planar Hyperspectral Imager With Small Smile and Keystone Based on Two Metasurfaces

“…In earlier work, compact spectrometers with nanometer spectral resolution based on a single metasurface have been demonstrated, which greatly reduces the weight and complexity of the system [27]- [29]. Subsequently, two kinds of spectral imagers utilizing metasurfaces have also been validated recently [30], [31]. One kind is a snapshot spectral imager, which is composed of three cascaded metasurface arrays [30].…”

“…Subsequently, two kinds of spectral imagers utilizing metasurfaces have also been validated recently [30], [31]. One kind is a snapshot spectral imager, which is composed of three cascaded metasurface arrays [30]. The corresponding spectral resolution is 7 nm and thus this imager belongs to the hyperspectral system.…”