Researchers generated 16.7 nm wavelength extreme-ultraviolet Poincaré beams at the FERMI free electron laser without relying on optical elements. The method of in situ Poincaré beam production in free electron lasers enables straightforward flexibility in the orientation and balance of polarization states, and can be extended to other vector beams and to shorter wavelengths.
- Jenny Morgan
- Primož Rebernik Ribič
- Erik Hemsing
