ASML Netherlands B.V

We propose a scheme to generate few-cycle vortices based on nonlinear Thomson scattering by microbunched electrons from a circularly polarized laser pulse with chirped frequency. At sufficiently high intensities, the generation of harmonics that carry orbital angular momentum occurs. At the same time, the electrons collectively act as a relativistic chirped mirror, which superradiantly reflects a chosen harmonic into a single localized beat.

Abstract The development of actinic mask metrology tools represents one of the major challenges to be addressed on the roadmap of extreme ultraviolet (EUV) lithography. Technological advancements in EUV lithography result in the possibility to print increasingly fine and highly resolved structures on a silicon wafer; however, the presence of fine-scale defects, interspersed in the printable mask layout, may lead to defective wafer prints.