"Single-cycle terahertz pulses with >0.2 V/Å field amplitudes via coherent transition radiation"

Dan Daranciang: John Goodfellow, Matthias Fuchs, Haidan Wen, Shambhu Ghimire, David A. Reis, Henrik Loos, Alan S. Fisher, Aaron M. Lindenberg; Applied Physics Letters, 10/07/11.

Additional Authors: John Goodfellow, Matthias Fuchs, Haidan Wen, Shambhu Ghimire, David A. Reis, Henrik Loos, Alan S. Fisher, Aaron M. Lindenberg

Abstract:

We demonstrate terahertz pulses with field amplitudes exceeding 0.2 V/A ° generated by coherent
transition radiation. Femtosecond, relativistic electron bunches generated at the Linac Coherent Light
Source are passed through a beryllium foil, and the emitted radiation is characterized as a function of
the bunch duration and charge. Broadband pulses centered at a frequency of 10 THz with energies of
140 lJ are measured. These far-below-bandgap pulses drive a nonlinear optical response in a silicon
photodiode, with which we perform nonlinear autocorrelations that yield information regarding the
terahertz temporal profile. Simulations of the spatiotemporal profile agree well with experimental
results.