Toward highly stable Terahertz Coherent Synchrotron Radiation at the synchrotron SOLEIL

The production of steady-state Coherent Synchrotron Radiation has been recently achieved in SOLEIL synchrotron using low-alpha configurations. Although the increase in THz intensity is advantageous for FTIR measurements, the signal-to-noise ratio is deteriorated by intensity fluctuations and aperiodic noise. However, we demonstrate here the possibility to use CSR as a source for FTIR spectroscopy at high resolution (10⁻³ cm⁻¹) by using a noise correction system based on double detection. Combined to the high stability optics of the infrared beamline AILES, it allows to extend the range of optimal use of the synchrotron source down to ∼0.2 THz (7 cm⁻¹).