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Arjun Nayak

Publications and source records attributed to Arjun Nayak.

3 recordsLinked to original sources

A High Intensity Attosecond Light Source in Compact Geometry at ELI ALPS User Facility

High-order harmonic generation (HHG) has become a standard technique for producing attosecond XUV pulses in the laboratory, yet the high flux necessary for nonlinear XUV photoionization remains accessible to only a few research groups. Here, we introduce the SYLOS Compact high-harmonic beamline at ELI ALPS, specifically designed to provide the flux required for non-linear optics in the XUV. We present a detailed characterization of the beam line demonstrating its capability to generate and utilize both intense attosecond pulse trains and isolated attosecond pulses. We further showcase the two-XUV-photon double ionization of neon (Ne) and argon (Ar), achieved in a user campaign. The results underscore the beamline's capability to support cutting-edge attosecond experiments and investigations of ultrafast electron dynamics on the attosecond scale.

physics.optics

Time Resolved Investigation of High Repetition Rate Gas Jet Target For High Harmonic Generation

High repetition rate gas targets constitute an essential component in intense laser matter interaction studies. The technology becomes challenging as the repetition rate approaches kHz regime. In this regime, cantilever based gas valves are employed, which can open and close in tens of microseconds, resulting in a unique kind of gas characteristics in both spatial and temporal domain. Here we characterize piezo cantilever based kHz pulsed gas valves in the low density regime, where it provides sufficient peak gas density for High Harmonic Generation while releasing significantly less amount of gas reducing the vacuum load within the interaction chamber, suitable for high vacuum applications. In order to obtain reliable information of the gas density in the target jet space-time resolved characterization is performed. The gas jet system is validated by conducting interferometric gas density estimations and high harmonic generation measurements at the Extreme Light Infrastructure Attosecond Light Pulse Source (ELI ALPS) facility. Our results demonstrate that while employing such targets for optimal high harmonic generation, the high intensity interaction should be confined to a suitable time window, after the cantilever opening. The measured gas density evolution correlates well with the integrated high harmonic flux and state of the art 3D simulation results, establishing the importance of such metrology.

physics.optics

Generation of micro-Joule level coherent quasi-continuum extreme ultraviolet radiation using multi-cycle intense laser-atom interactions

In the present work we report on the current progress of the recently constructed GW attosecond extreme ultraviolet (XUV) source developed at the Institute of Electronic Structure and Laser of the Foundation for Research and Technology-Hellas (I.E.S.L-FO.R.T.H.). By the implementation of a compact-collinear polarization gating arrangement, the generation of a broadband, coherent XUV quasi-continuum produced by the interaction of a many-cycle infrared field with a gas phase medium is achieved. The spectral width of the XUV emission generated in Xenon, is spanning in the range of 17-32 eV and can support isolated pulses of duration in the range from 0.4 fs to 1.3 fs and pulse energy in the 1 μJ level.Theoretical calculations, taking into account the experimental conditions of this work, are supporting the observations, offering also an insight regarding the temporal profile of the emitted radiation. Finally, the high intensity of the produced XUV pulses has been confirmed by investigating the two-XUV-photon double ionization process of Argon atoms. The demonstrated results inaugurate the capability of the beamline to produce intense isolated attosecond pulses towards their exploitation in studies of non-linear XUV processes, attosecond pulse metrology and XUV pump XUV probe experiments.

physics.atom-ph