Scientists in Israel and in the US have experimentally investigated the optical properties of nonlinear photonic quasicrystals, two-dimensional structures with long-range order but no periodicity. The results may offer insights into various fundamental physical phenomena involving quasiperiodic structures. In the work, which they reported in the April 27 issue of Nature, the researchers from Technion — Israel Institute of Technology in Haifa, Tel Aviv University, the University of Central Florida in Orlando and Princeton University in New Jersey — created quasicrystals with decagonal symmetry in the photosensitive material strontium barium niobate with five overlapping beams of 488-nm light from Coherent Inc. argon-ion lasers (far left). Images of the structure produced by Brillouin zone spectroscopy (left), performed using Spiricon Inc. laser beam analyzers and Cohu Inc. cameras, confirmed its quasicrystal status. The scientists demonstrated the “healing” of an induced defect in a dynamic quasiperiodic lattice, confirming 20-year-old theoretical predictions. The work sets the stage for the study of other nonlinear quasiperiodic systems.