Spacetime in Lenses: How Einstein's Physics Enables Super-Resolution express
A river flows in one direction, but a wave on its surface travels in the opposite direction. The same splitting happens in hyperbolic materials: the energy of a light wave and its fronts diverge, preventing a sharp lens from being created. Physicists tamed this chaos by applying the geometry of spacetime from special relativity, created by Einstein based on the work of Lorentz. The material's properties are transformed into a metric, where the speed of light plays the role of a fundamental constant, and everything falls into place.
Scientists derived universal formulas that allow designing lenses that focus light with enormous precision, bypassing the natural blur inherent to any lens. Such optics distinguish details hundreds of times finer than the wavelength — for example, a magnifying glass capable of reading text on an atom. In the experiment, a flat lens was simulated for the mid-infrared range, using polaritons — quantum oscillations of the crystal lattice.
The same equations that predict the curvature of spacetime around stars helped design lenses capable of distinguishing molecular-sized details.