A tunable XUV monochromatic light source based on the time preserving grating selection of high-order harmonic generation

Niu Yong^{1, 2}, Liang Hongjing^{1, 2}, Liu Yi^{1, 2}, Liu Fangyuan^{1, 2}, Ma Ri^{1, 2, †}, Ding Dajun^{1, 2, ‡}

(color online) The measured spectral profile for the H23 harmonic radiation. The central photon energy is 35.7 eV and the FWHM is 1 eV, as indicated by the black arrows. The red line shows the spectral profile of H23 from the home-built flat field spectrometer in the same experiment condition and the FWHM is 0.9 eV, as denoted by the red arrows.