Characterization of the high harmonics source for the VUV ellipsometer at ELI Beamlines

Abstract

In this paper, the authors present the characterization experiments of a 20fs vacuum ultraviolet beam from a high harmonic generation source. The beam hits a silicon sample and passes a triple reflection gold polarizer located inside an ultrahigh vacuum chamber. The polarizer's Malus curve was obtained; the total acquisition time for each point of the curve was 30s. This aims to be the first vacuum ultraviolet time-resolved user station dedicated to ellipsometry. The high harmonic beam is generated by a 12mJ, 1kHz, 20fs, in-house-developed laser and detected by a back-illuminated charge-coupled device.