The 8th International Conference on Matter and Radiation at Extremes (ICMRE2025)

Vector beams, characterized by space-variant polarization states and complex spin orbital angular momentum (SAM-OAM) couplings, have great potential for applications in various fields. Although vector beams can be readily obtained in the visible spectral range, the generation of short-wavelength extreme-ultraviolet (EUV) vector beams remains challenging, especially for the case of high pulse intensity. Here, we investigate the generation of higher-order harmonic vector beams from relativistic laser-plasma interactions. Theoretical analysis and 3D PIC simulations show that the polarization states and OAM of harmonic vector beams can be controlled completely by topological charges of incident light. Interestingly, for harmonic vector beams with total non-zero OAM, both intensity and electric field vectors rotate with longitudinal position (time). Attributed to the uniqueness of vector beams, using either few-cycle driving pulse or polarization gating technique for multi-cycle driving pulse, an intense isolated attosecond pulse with spiral wavefront and spatially-tailored polarization is obtained. Our work opens up the possibility of more applications for vector beams, such as ultrafast imaging and dynamics probing in polarization-dependent systems.
 

laser-plasma interaction,high-order harmonic generation,vector beam