August 10, 2015

Camera for the Nano-Cosmos

Researchers from the HZDR and TU Dresden initially study a known thin-layer sample
made of silicon and germanium using their novel nanoscope. Short Laser pulses excite
the electrons in the bright stripes, which are several hundred nanometers wide,
whereby the otherwise transparent sample at these locations becomes reflexive.
Image: TU Dresden

Dresden researchers develop an all-purpose optical method for observing physical, chemical or biological processes at the nanoscale.

(August 10, 2015)  To gain even deeper insights into the smallest of worlds, the thresholds of microscopy must be expanded further. Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the TU Dresden, in cooperation with the Freie Universität Berlin, have succeeded in combining two established measurement techniques for the first time: near-field optical microscopy and ultra-fast spectroscopy. Computer-assisted technology developed especially for this purpose combines the advantages of both methods and suppresses unwanted noise. This makes highly precise filming of dynamic processes at the nanometer scale possible. The results were recently published in the research journal Scientific Reports (DOI: 10.1038/srep12582).

Many important but complex processes in the natural and life sciences, for example, photosynthesis or high-temperature superconductivity, have yet to be understood. On the one hand, this is due to the fact that such processes take place on a scale of a millionth of a millimeter (nanometer) and therefore cannot be observed by conventional optical microscopic imaging. On the other hand, researchers must be able to precisely observe very rapid changes in individual stages to better understand the highly complex dynamics. The development of high-resolution temporal and spatial technologies has therefore been promoted for decades.

The new camera from Dresden combines the advantages of two worlds: microscopy and ultra-fast spectroscopy. It enables unaltered optical measurements of extremely small, dynamic changes in biological, chemical or physical processes. The instrument is compact in size and can be used for spectroscopic studies in a large area of the electromagnetic spectrum. Time increments from a few quadrillionths of a second (femtoseconds) up to the second range can be selected for individual images. “This makes our nanoscope suitable for viewing ultra-fast physical processes as well as for biological process, which are often very slow,” says the HZDR’s Dr. Michael Gensch.

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