Phys.org July 3, 2024 Phonon engineering at the nanoscale holds immense promise for a myriad of applications. However, the design of phononic devices continues to rely on regular shapes chosen according to long-established simple rules. Researchers in Japan demonstrated an inverse design approach to create a two-dimensional phononic metasurface exhibiting a highly anisotropic phonon dispersion along the main axes of the Brillouin zone. A partial hypersonic bandgap was present along one axis, with gap closure along the orthogonal axis which was achieved through genetically optimized unit cells, with shapes exceeding conventional intuition. They experimentally validated their theoretical predictions using Brillouin […]
Category Archives: Photonic crystals
Light stands still in a deformed crystal
Phys.org April 24, 2024 Although in electronic crystals, magnetic fields can be used to induce a multitude of unique phenomena, the uncharged nature of photons necessitates alternative approaches to bring about similar control over photons at the nanoscale. Researchers in the Netherlands demonstrated experimentally pseudomagnetic fields in two-dimensional photonic crystals through engineered strain of the lattice. Taking advantage of the photonic crystal’s design freedom, they realized domains of opposite pseudomagnetic field and observed chiral edge states at their interface. They revealed that the strain-induced states could achieve remarkably high quality factors despite being phase matched to the radiation continuum. Together […]
Steering light to places it isn’t supposed to go
Phys.org April 28, 2021 The best materials for housing qubits and certain other optically activated objects typically reflect incident light. By stopping externally applied light from reaching its target, this reflectivity presents a challenge for controlling optically integrated devices. Researchers in the Netherlands have demonstrated a way of guiding light along an arbitrary path through a material by patterning the light’s phase. They shone an infrared beam into the edge of a 2D silicon crystal containing a periodic arrangement of air-filled pores. A large fraction of the light was reflected back along the beam, but because of disorder in the […]