Ultrashort laser pulses have enabled scientists and physicians to carry out high-precision material analyses and medical procedures. Physicists from the University of Bayreuth and the University of Göttingen have now discovered a new method for adjusting the extremely short time intervals between laser flashes with exceptional speed and precision. The intervals can be increased or decreased as needed, all at the push of a button. Potential applications range from laser spectroscopy to microscopy and materials processing. The researchers have now presented their latest findings in the journal Nature Photonics.
Laser pulses have long been utilized in research laboratories, industrial production, and medical therapies. In these applications it is often crucial that the pulses – also known as optical solitons – occur at certain intervals.
Using a special high-speed measurement technique, the researchers have now been able to show how a short-pulse laser widely applied in research can be made to automatically generate pairs of light pulses separated by the desired interval.
All that is required are small disturbances in the green optical "pump beam” (which generates the laser pulses) triggered by electric signals.
The new process centres on the targeted manipulation of solitons, wave packets that can occur in pairs in ultrashort laser pulses. "The resonance excitation and the short disturbance of soliton pairs trigger effects that can be used to specifically control ultrashort laser pulses.
This opens up an exciting new area of research with a yet unforeseeable range of possible applications," said Prof. Dr. Georg Herink from Bayreuth, corresponding author of the new study. "At the right frequency, a tiny external modulation of the laser is all you need, and ultrashort laser pulses are set into reciprocal, resonant oscillation.
Similar phenomena can be observed in water molecules heated in the microwave," added lead author Felix Kurtz from Göttingen.
The newly published findings show that in the future, ultra-short pulse lasers will not only be considered as a tool, but also remain a fascinating object of research.
Prof. Dr. Georg Herink
Experimental Physics VIII
University of Bayreuth
Phone: +49 (0)921 / 55-3161
F. Kurtz, C. Ropers, G. Herink: Resonant excitation and all-optical switching of femtosecond soliton molecules. Nature Photonics (2019), DOI: http://dx.doi.org/10.1038/s41566-019-0530-3
Christian Wißler | Universität Bayreuth
A one-way street for light
14.11.2019 | Rheinische Friedrich-Wilhelms-Universität Bonn
TU Graz researchers develop new 3D printing for the direct production of nanostructures
14.11.2019 | Technische Universität Graz
The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...
Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.
New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...
If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.
Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...
Quantum-based communication and computation technologies promise unprecedented applications, such as unconditionally secure communications, ultra-precise...
In two experiments performed at the free-electron laser FLASH in Hamburg a cooperation led by physicists from the Heidelberg Max Planck Institute for Nuclear physics (MPIK) demonstrated strongly-driven nonlinear interaction of ultrashort extreme-ultraviolet (XUV) laser pulses with atoms and ions. The powerful excitation of an electron pair in helium was found to compete with the ultrafast decay, which temporarily may even lead to population inversion. Resonant transitions in doubly charged neon ions were shifted in energy, and observed by XUV-XUV pump-probe transient absorption spectroscopy.
An international team led by physicists from the MPIK reports on new results for efficient two-electron excitations in helium driven by strong and ultrashort...
05.11.2019 | Event News
30.10.2019 | Event News
02.10.2019 | Event News
14.11.2019 | Materials Sciences
14.11.2019 | Health and Medicine
14.11.2019 | Materials Sciences