A metalens replaces a curved glass lens with a flat, wafer-fabricated array of subwavelength nanostructures that impose a designed phase profile on light; it is now delivering measured wins in narrowband laser, sensing and instrument optics while still failing system-level tests as a full-colour imaging eyepiece.
Summary
A conventional lens bends light by accumulating optical path difference through curved bulk glass. A metalens does the same job in a film a fraction of a wavelength thick, by patterning a dielectric surface with a dense array of subwavelength scatterers (meta-atoms, typically nanopillars or nanorods) whose local geometry sets the local phase delay. Arrange the phase to be hyperbolic and you get a focus. Because the whole device is a lithographic pattern on a flat wafer, it can in principle be made with semiconductor tooling, integrated monolithically with other photonics, and made from materials that no one can grind into a lens shape.
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Assessment drafted 2026-08-31 from up to 15 KB sources using the technology-scorecard framework; scores are a draft read pending review.