All femtosecond optical pump and x-ray probe: holey-axicon for free electron lasers. (9th February 2021)

• Record Type: Journal Article
• Authors: Anand, V; Maksimovic, J; Katkus, T; Ng, S H; Ulčinas, O; Mikutis, M; Baltrukonis, J; Urbas, A; Šlekys, G; Ogura, H; Sagae, D; Pikuz, T; Somekawa, T; Ozaki, N; Vailionis, A; Seniutinas, G; Mizeikis, V; Glazebrook, K; Brodie, J P; Stoddart, P R; Rapp, L; Rode, A V; Gamaly, E G; Juodkazis, S
• Is Part Of: JPhys photonics. Volume 3:Number 2(2021)
• Publication Date: 2021-02-09
• Subjects: x-rays -- free electron laser (FEL) -- ultra-short phenomena -- pump-probe -- warm-dense matter -- astrophotonics -- co-axial volumetric interaction diagnostics; Photonics -- Periodicals; 621.365
• DOI: 10.1088/2515-7647/abd4ef
• Languages: English
• ISSNs: 2515-7647

Abstract

Abstract: We put forward a co-axial pump (optical)-probe (x-rays) experimental concept and show performance of the optical component. A Bessel beam generator with a central 100 µ m diameter hole (on the optical axis) was fabricated using femtosecond (fs) laser structuring inside a silica plate. This flat-axicon optical element produces a needle-like axial intensity distribution which can be used for the optical pump pulse. The fs-x-ray free electron laser (X-FEL) beam of sub-1 µ m diameter can be introduced through the central hole along the optical axis onto a target as a probe. Different realisations of optical pump are discussed. Such optical elements facilitate alignment of ultra-short fs-pulses in space and time and can be used in light–matter interaction experiments at extreme energy densities on the surface and in the volume of targets. Full advantage of ultra-short 10 fs-X-FEL probe pulses with fs-pump (optical) opens an unexplored temporal dimension of phase transitions and the fastest laser-induced rates of material heating and quenching. A wider field of applications of fs-laser-enabled structuring of materials and design of specific optical elements for astrophotonics is presented.