Terahertz coherent synchrotron radiation: ultrafast characterization and control at Synchrotron SOLEIL

We present recent results on the characterization and control of the coherent terahertz pulses emitted by synchrotron radiation facilities. We first show novel ultrafast single-shot measurements techniques now allow these sources to be fully characterized in a pulse-by-pulse basis [1]. Then we present a novel feedback method that enables the dynamics of these sources to be fully controlled [2]. This opens the way to novel sources of stable THz radiation, and to high repetition-rate spectroscopic applications.