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.