Showing posts with label Thomas Feurer. Show all posts
Showing posts with label Thomas Feurer. Show all posts

Tuesday, July 15, 2014

Abstract-Split ring resonator based THz-driven electron streak camera featuring femtosecond resolution



http://www.nature.com/srep/2014/140710/srep05645/full/srep05645.html



Through combined three-dimensional electromagnetic and particle tracking simulations we demonstrate a THz driven electron streak camera featuring a temporal resolution on the order of a femtosecond. The ultrafast streaking field is generated in a resonant THz sub-wavelength antenna which is illuminated by an intense single-cycle THz pulse. Since electron bunches and THz pulses are generated with parts of the same laser system, synchronization between the two is inherently guaranteed.

Monday, July 14, 2014

Abstract-THz generation by optical rectification of near-infrared laser pulses in the organic nonlinear optical crystal HMQ-TMS



Fabian D. J. Brunner, Seung-Heon Lee, O-Pil Kwon, and Thomas Feurer  »View Author Affiliations

Optical Materials Express, Vol. 4, Issue 8, pp. 1586-1592 (2014)
http://dx.doi.org/10.1364/OME.4.001586

http://www.opticsinfobase.org/ome/abstract.cfm?uri=ome-4-8-1586
We show that the organic electro-optic crystal HMQ-TMS [2-(4-hydroxy-3-methoxystyryl)-1-methylquinolinium 2,4,6-trimethylbenzenesulfonate] has favorable properties for the parametric generation of THz waves in a collinear type-0 phase-matching scheme, i.e., a low absorption coefficient at wavelengths from 800 to 1500 nm (α < 1.5cm−1), a relatively low absorption coefficient at frequencies from 0.3 to 1.5 THz (α < 100 cm−1), and a large coherence length in these spectral ranges (lc > 0.5 mm). We demonstrate efficient generation of broadband THz pulses through optical rectification of sub-picosecond laser pulses in a 0.2 mm thick HMQ-TMS crystal at the wavelength of 1000 nm. The energy conversion efficiency achieved in this crystal was 41 times higher than the one achieved in a 0.3 mm thick GaP crystal, which is an often used material for collinearly phase-matched THz generation at this laser wavelength. The peak amplitudes of the THz signal obtained with the HMQ-TMS crystal were 5.4 times larger in the time-domain and 7.1 times larger in the frequency-domain than the ones obtained with the GaP crystal.
© 2014 Optical Society of America

Wednesday, August 7, 2013

Abstract-Coherent control of terahertz meta-materials


Florian Enderli and Thomas Feurer
Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland 


We present coherent control of a THz meta-material. Specifically, we show in detail the time and frequency dependent response of a single and a double split ring resonator upon excitation with a shaped THz field. Through far- and near-field measurements, we confirm the coherence transfer from the tailored THz field to the system and back to the radiated field and we demonstrate selective excitation of a designated system resonance with a suitably shaped THz pulse.