W. P. E. M. Op 't Root's research while affiliated with Eindhoven University of Technology and other places

Publications (4)

Article
Full-text available
Terahertz (THz) pulses are applied in areas as diverse as materials science, communication and biosensing. Techniques for subwavelength concentration of THz pulses give access to a rapidly growing range of spatial scales and field intensities. Here we experimentally demonstrate a method to generate intense THz pulses on a metal wire, thereby introd...
Data
The movie is an animation of the experiment (with voice-over) which illustrates the method and gives a feeling for the actual dimensions of the setup.
Article
We propose to generate terahertz surface plasmon polaritons (SPPs) on a metal wire by launching electron bunches onto a tapered end of the wire. To show the potential of this method, we solve Maxwell’s equations for the appropriate boundary conditions. The metal wire tip is modeled by a perfectly conducting semi-infinite cone. It is shown that the...
Article
Full-text available
We present a method for producing sub-100 fs electron bunches that are suitable for single-shot ultrafast electron diffraction experiments in the 100 keV energy range. A combination of analytical results and state-of-the-art numerical simulations show that it is possible to create 100 keV, 0.1 pC, 20 fs electron bunches with a spotsize smaller than...

Citations

... In this paper we describe the application of the electro-optic sampling (EOS) technique to the characterization of the radiation pulses from the UCLA Pegasus THz-FEL [19]. EOS has been successfully used in many accelerator beamlines to characterize radiation from electron beams (transition radiation, diffraction radiation and other coupling schemes [21][22][23]) and in laser-based THz generation setups [24,25]. To our knowledge this is the first time that a THz-FEL operating in the zero-slippage regime is characterized by EOS. ...
... In this mechanism, an instantly excited, radially polarized strong electric field would force the laser-accelerated electrons to gyrate around the wire target, as akin to the helical undulator in an FEL. Meanwhile, the metal wire itself also serves as a natural Dongdong I waveguide for the THz synchrotron radiation which is collimated and guided immediately by the wire as THz surface plasmon polaritons (SPPs) and then emitted from the end of the wire [26,27]. Consequently, emitted THz synchrotron radiation does not rely on the laser-plasma interaction directly as in the case of foil target. ...
... Examples include the use of radio-frequency (RF) accelerating cavities where electric fields approaching 100 MV/m can be used to quickly boost the energy of the electrons to the MeV range (Wang et al., 1996(Wang et al., , 2006. RF fields can also be employed to reverse the space charge induced temporal expansion to retrieve very short bunches at the sample plane (Chatelain et al., 2012;Gao et al., 2012;Gliserin et al., 2012;Otto et al., 2017;van Oudheusden et al., 2007). RF-based deflecting cavities have been used as ultrafast streak-cameras (Musumeci et al., 2009;van Oudheusden et al., 2010), high-speed beam blankers , or in high resolution time-of-flight spectrometers (Verhoeven et al., 2016). ...