Speaker
Description
Polarization control of high-intensity coherent X-ray light is essential for many experiments, including magnetic spectroscopy and studies of chiral molecular structure. However, most free-electron laser facilities rely on planar undulators for light generation, which are generally unable to provide polarization tunability. Counterintuitively, analytical solutions of Maxwell's equations predict a vertical polarization component in the second harmonic of planar undulator radiation, a feature that offers a potential route to polarization control without the need for specialized undulator designs. Understanding the polarization structure of higher harmonics is thus crucial for extending the capabilities of these facilities. Using an angle-resolving electron time-of-flight (ARTOF) detector, we measure the out-of-plane polarization of first- and second-harmonic soft X-ray pulses at the Linac Coherent Light Source (LCLS). We present results of varying polarization structures between the fundamental and second harmonic and demonstrate that ARTOF-based measurements provide a practical method for characterizing FEL polarization. These results suggest that polarization tunability may be more broadly accessible at FEL facilities than previously recognized.
| I have read and accept the Privacy Policy Statement | Yes |
|---|