Extreme Ultraviolet Fourier-Transform Spectroscopy with High Order Harmonics

Abstract

Extreme ultraviolet fourier-transform spectroscopy with high order harmonicsKovacev, M; Fomichev, SV; Priori, E; Mairesse, Y; Merdji, H; Monchicourt, P; Breger, P; Norin, Johan; Persson, Anders; Lhuillier, A; Wahlström, Claes-Göran; Carre, B; Salieres, P General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. We demonstrate a new scheme for extreme ultraviolet (xuv) Fourier-transform spectroscopy based on the generation of two phase-locked high-harmonic beams. It allows us to measure for the first time interferograms at wavelengths as short as 90 nm, and open the perspective of performing high-resolution Fourier-transform absorption spectroscopy in the xuv. Our measurements also demonstrate that a precise control of the relative phase of harmonic pulses can be obtained with an accuracy on an attosecond time scale, of importance for future xuv pump-xuv probe attosecond spectroscopy. Extreme Ultraviolet Fourier-Transform Spectroscopy with High Order Harmonics

Spatially resolved Fourier transform spectroscopy in the extreme ultraviolet

“…This radiation is typically emitted in a train of attosecond pulses with excellent spatial and temporal coherence, as shown in various interferometric and spectroscopic measurements [4][5][6][7][8][9][10][11][12]. As a result, interferometry with high harmonics found important applications in e.g.…”

“…Two main types of HHG interferometers have been devised. In one scheme, the near-infrared fundamental driving pulse is split into two phase-locked pulses with an adjustable time delay, and this pulse pair is subsequently used for HHG [5,[7][8][9]. Although this method has been successfully used it is typically limited by the stability of the optical interferometer.…”

Octave-spanning hyperspectral coherent diffractive imaging in the extreme ultraviolet range

“…It has been shown that two sources have relative timing jitter in the zeptosecond range [25]. Since beamsplitters are not readily available in the HHG spectral range, and spatial wavefront division cannot create two closely-separated sources [26], we instead split the driving infrared femtosecond laser pulse and create two separate foci in the same gas source [18,19,27]. The two 800-nm 50-fs laser pulses are delayed in a common-path arrangement with a time-delay step size of 27 attoseconds over a total delay of 27 fs.…”

“…A delay jitter of a tenth of a wavelength in FTS can deteriorate the quality of retrieved power spectrum [18]. The accuracy of the delay step limits the highest optical frequency that can be spectrally resolved.…”

“…Here we utilize the full bandwidth of an HHG source by applying Fourier transform spectroscopy (FTS) [18,19] at every pixel in the diffraction image. FTS does not employ slits, so all the photons from the entire spectrum are used to form an image.…”