Compact Spectroscopy Techniques with Metasurface Optics

Recent advances in metasurface optics have enabled the development of ultracompact spectrometers that combine spectral analysis with miniaturised form factors. By engineering arrays of subwavelength nanostructures on planar substrates, metasurfaces can replace bulky refractive components with ultrathin, lithographically defined elements. Techniques such as folded metasurface architectures confine light within slender glass slabs, while multifunctional metalenses employ phase and wavelength multiplexing to map distinct spectral bands onto a single focal plane. Hybrid elements, integrating microlens arrays and diffraction gratings, further enhance throughput and channel count without sacrificing resolution. These innovations promise portable, on-chip spectral analysers for environmental sensing, medical diagnostics, hyperspectral imaging and wearable photonic devices, offering robust, mass-producible platforms that bring laboratory-grade performance to field-deployable instruments.

Research from Nature Portfolio

A foundational demonstration employed a folded metasurface design within a 1 mm-thick glass slab of 7 mm³ volume. Three reflective dielectric metasurfaces were fabricated in a single lithographic step on one substrate face, serving simultaneously as wavefront controllers and propagation medium. This configuration achieved a resolution of around 1.2 nm over the 760–860 nm band, resolving more than 80 spectral points. The folded layout reduces the optical path length while preserving high resolving power, and its planar integration offers enhanced mechanical robustness. Such compact architectures are readily extendable to hyperspectral imagers, computational optical processors and interferometric systems, signalling a versatile route to centimetre-scale spectroscopic devices.

Compact Spectroscopy Techniques with Metasurface Optics publication trend

The graph below shows the total number of articles in compact spectroscopy techniques with metasurface optics across all publications each year (not limited to Nature Index journals).

Technical terms

Metasurface: A planar arrangement of engineered nanostructures that imparts arbitrary phase, amplitude or polarization changes to incident light.

Metalens: A flat lens formed by a metasurface, designed to focus or shape light through spatially varying phase shifts.

Wavelength multiplexing: A method of encoding or separating optical wavelengths by directing each spectral component to distinct spatial locations.

Microlens array grating: A hybrid optical element integrating an array of microlenses with a diffraction grating to achieve simultaneous focusing and dispersion in a compact form.

References

1. Compact multi-foci metalens spectrometer. Light: Science & Applications (2023).
2. A Microlens Array Grating for Miniature Multi-Channel Spectrometers. Sensors (2023).
3. Compact folded metasurface spectrometer. Nature Communications (2018).