Recreating the natural light-harvesting nanorings in photosynthetic bacteria

Science Daily  January 31, 2023 Photosynthesis in plants and some bacteria relies on light-harvesting (LH) supramolecules which come in different structures. So far, these LH molecules have not been artificially prepared. Researchers in Japan demonstrated that mixing a chlorophyll derivative with naphthalenediamide in an organic solvent leads to the formation of dimers that spontaneously self-assembled into ring-shaped structures, each several hundred nanometers in diameter. They observed that chlorophyll dimers, molecules composed of two chlorophyll units linked by naphthalene, initially self-assembled into stable wavy nanofibers. Upon heating these nanofibers at 50°C, they disassembled into smaller nanoring precursors whose ends eventually joined […]

Physicists develop a perfect light trap

Phys.org  August 25, 2022 One of the key insights of non-Hermitian photonics is that well-established concepts such as the laser can be operated in reverse to realize a coherent perfect absorber (CPA). Although conceptually appealing, such CPAs are limited so far to a single, judiciously shaped wavefront or mode. An international team of researchers (Israel, Austria) built a “light trap” around the thin layer using mirrors and lenses, in which the light beam is steered in a circle and then superimposed on itself—exactly in such a way that the beam of light blocks itself and can no longer leave the […]