In situ frequency gating and beam splitting of vacuum- and extreme-ultraviolet pulses.

ABSTRACT: Monochromatization of high-harmonic sources has opened fascinating perspectives regarding time-resolved photoemission from all phases of matter. Such studies have invariably involved the use of spectral filters or spectrally dispersive optical components that are inherently lossy and technically complex. Here we present a new technique for the spectral selection of near-threshold harmonics and their spatial separation from the driving beams without any optical elements. We discover the existence of a narrow phase-matching gate resulting from the combination of the non-collinear generation geometry in an extended medium, atomic resonances and absorption. Our technique offers a filter contrast of up to 10⁴ for the selected harmonics against the adjacent ones and offers multiple te

SUBMITTER: Rajeev R 

PROVIDER: S-EPMC6059825 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature