We present a new approach (demonstrated experimentally and through modeling) to characterize the spectral envelope of a terahertz (THz) pulse in a single shot. The coherent THz pulse is produced by a femtosecond electron bunch and contains information on the bunch duration. The technique, involving a single low-power laser probe pulse, is an extension of the conventional spectral encoding method (limited in time resolution to hundreds of femtoseconds) into a regime only limited in resolution by the laser pulse length (tens of femtoseconds). While only the bunch duration is retrieved (and not the exact charge profile), such a measurement provides a useful and critical parameter for optimization of the electron accelerator.
© 2008 Optical Society of America
Lasers and Laser Optics
Original Manuscript: February 5, 2008
Revised Manuscript: April 16, 2008
Manuscript Accepted: April 17, 2008
Published: May 23, 2008
J. van Tilborg, Cs. Tóth, N. H. Matlis, G. R. Plateau, and W. P. Leemans, "Single-shot measurement of the spectral envelope of broad-bandwidth terahertz pulses from femtosecond electron bunches," Opt. Lett. 33, 1186-1188 (2008)