discovered_01_2016 - Shifting the Boundaries in the Nano World

WWW.HZDR.DE 12 13 TITLE // THE HZDR RESEARCH MAGAZINE // Physicists at TU Dresden and HZDR are bypassing the boundaries of optics with near-field microscopy and demonstrating how a smooth transition from university research to extra-mural science can work. Looking into a microscope always means immersing ourselves into worlds that are usually hidden from us. Miniscule fibers of material, the tiniest bacteria and individual grains of dust suddenly tower up like skyscrapers or planet-like formations. Modern research has long since started using the nanometer range – that is, millionths of a millimeter – for its measurements. But here, classic microscopy soon reaches its absolute boundaries – the so-called Abbe limit. From this point onwards, light diffraction means that individual points can no longer be distinguished. The highest possible resolution in a traditional optical microscope is roughly half of the wavelength of the light used. Thus even by employing particularly short-wave ultraviolet light it is barely possible to examine details smaller than 200 nanometers. By comparison, the structures of modern microchips are often significantly smaller and many viruses barely exceed 100 nanometers. Firing infrared radiation at the nanotip If we want to investigate the nano world with long-wave infrared radiation, this is a serious obstacle, as the physicist Stephan Winnerl of HZDR’s Institute of Ion Beam Physics and Materials Research explains: "On the one hand, electromagnetic radiation is very suitable for a lot of physical studies because it can easily penetrate matter and excite oscillations in molecules and solids. On the other hand, with the increasing wavelength, the resolution gets ever worse." _TEXT . Christian Döring SHIFTING THE BOUNDARIES IN THE NANO WORLD RECORD-BREAKING: Denny Lang, doctoral candidate at HZDR, adjusts the low-temperature near-field microscope at the Free- Electron Laser FELBE. Photo: Oliver Killig

Seitenübersicht