A silicon nitride chip patterned with a 13-sided "einstein" tile scattered laser light into a pinwheel of bright Bragg peaks, showing a never-repeating photonic crystal can still produce long-range order.
Hundreds of thousands of holes, each about 100 nanometers in radius, were etched into a roughly 0.5-millimeter chip to test whether the aperiodic tiling could steer light differently from standard repeating photonic crystals.
The tile's lack of mirror symmetry gave the diffraction pattern chirality, and the team found clockwise and counterclockwise circularly polarized light scattered differently—an effect ordinary mirror-symmetric quasicrystals cannot produce.
The result builds on the 2023 discovery of the single-shape "einstein" tile and points to future photonic-chip designs for optical communications and computing that manipulate light inside the device, not just off its surface.