Open AccessPolarimetry of a single-order circularly polarized high harmonic separated by a time-delay compensated monochromator
Author(s) -
Kengo Ito,
Eisuke Haraguchi,
Keisuke Kaneshima,
Taro Sekikawa
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.382423
Subject(s) - optics , monochromator , elliptical polarization , circular polarization , physics , extreme ultraviolet , polarization (electrochemistry) , high harmonic generation , monochromatic color , grating , diffraction grating , diffraction , linear polarization , materials science , optoelectronics , laser , wavelength , chemistry , microstrip
Monochromatic elliptically polarized (CP) ultrashort extreme ultraviolet (EUV) light source with higher ellipticity than 0.80 is developed for the investigation of molecular chirality and electromagnetic phenomena. Elliptically polarized 47-nm high harmonic (HH) is monochromatized from the comb spectrum of HHs by a time-delay compensated monochromator (TDCM) consisting of a pair of Pt-coated toroidal gratings. The ellipticity of EUV light, which is higher than 0.10 at high harmonic generation, is compensated by the anisotropies of the diffraction efficiency and of the phase shift of the toroidal gratings. The degree of polarization is also improved by the diffraction on the gratings. Prior to the polarization compensation, the unknown optical parameters of the toroidal grating at 47 and 50 nm were determined using CP light source and Mueller matrices. The optical parameters were found to be close to those of coated substance Pt. The single-order CP HH light source will be versatile both for spectroscopy and for diffractive imaging.