Plasma mirror and temperature evolution for short pulse KrF lasers

Földeş, I; Csáti, Dániel; Szűcs, Ferenc Lajos; Szatmàri, S.

doi:10.1080/10420151003715457

Cited by 12 publications

(10 citation statements)

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“…10 8 W/cm 2 after 3 passes in the amplifier) the reflectivity drops below 50% [16] in agreement with the early observations of Fedosejevs et al [14]. The nearly perpendicular angle of incidence is needed as well, because in the first plasma-mirror experiments with the KrF laser [17] the angle of incidence was 45°and the reflectivity was as low as 30%. The shot-to-shot variation of reflectivity is attributed to the beam quality nonuniformities due to the shot-to-shot variation of the discharge-pump of the laser.…”

Section: Experimental Arrangementsupporting

confidence: 87%

Plasma Mirrors for Cleaning Laser Pulses from the Infrared to the Ultraviolet

Földeş

Gilicze

Kovács

et al. 2018

EPJ Web of Conferences

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Ultrashort laser pulses are generally preceded by prepulses which - in case of high main pulse intensities - may generate preplasmas on solid surfaces, thus making the initial conditions for the interactions ambiguous. Infrared laser systems applied successfully, with high efficiency self-induced plasma mirrors for improving the contrast of the beam. Short wavelength laser beams however have a larger critical density in the plasma, and due to their deeper penetration the absorption is higher, the reflectivity, and the corresponding plasma mirror efficiency is lower. We show herewith that with carefully planned boundary conditions plasma mirrors can reach up to 70% efficiency even for KrF laser radiation. Our observations can be qualitatively explained by the classical Drude model. The high reflectivity allows the use of plasma mirrors even after the final amplification or before the last amplifier. Different arrangement proposals for its integration to our high power KrF laser system are given as well.

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Section: Experimental Arrangementsupporting

confidence: 87%

Plasma Mirrors for Cleaning Laser Pulses from the Infrared to the Ultraviolet

Földeş

Gilicze

Kovács

et al. 2018

EPJ Web of Conferences

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“…Increasing the intensity from 10 15 to 10 18 W cm −2 , the reflectivity shows a monotonic decrease. Note that former plasma mirror experiments performed with KrF lasers where increasing reflectivity was measured for the 45°angle of incidence showed saturation above 10 14 W cm −2 and a strong decrease above 10 15 W cm −2 intensity [30]. In the present work, however, the reflectivity drops below 10% above 10 18 W cm −2 , i.e.…”

Section: Resultscontrasting

confidence: 64%

Reflectivity and spectral shift from laser plasmas generated by high-contrast, high-intensity KrF laser pulses

Kovács

Bali

Gilicze

et al. 2020

Phil. Trans. R. Soc. A.

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The energy and spectrum of the reflected 248 nm radiation are studied from solid targets up to 1.15 × 10 18 W cm −2 intensity. The experiments used the 700 fs directly amplified pulses of the KrF system which was cleaned from prepulses with the new Fourier-filtering method providing 12 orders of magnitude temporal contrast. Increasing the intensity from 10 15 W cm −2 results in increasing absorption up to more than 90% above 10 18 W cm −2 . This is accompanied by increasing x-ray conversion exhibiting a less steep power law dependence for low-Z matter than for gold. Strong blue shift of the reflected radiation from the backward propagating plasma was observed. It is shown that in the case of KrF laser pulses of highest contrast, vacuum heating can be one of the dominant absorption mechanisms. This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 1)’.

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“…One of the most efficient methods to remove prepulses is based on the self-induced plasma shuttering or plasma mirror technique [6], which was successfully demonstrated for short-pulse KrF laser systems, too [7]. If the intensity of the laser pulse falling onto a transparent solid material is chosen so that only the leading edge of the main pulse is above the plasma formation threshold, prepulses or the pedestal of lower intensity will be suppressed, improving the contrast up to several orders of magnitude.…”

Section: Introductionmentioning

confidence: 99%

Improvement of the spatial and temporal contrast of short-pulse KrF laser beams

Szatmàri

Dajka

Barna

et al. 2013

EPJ Web of Conferences

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Abstract. Important figure of merit of high-intensity laser systems is the temporal and spatial quality of their pulses. Spatial filtering is a well known technique to improve the spatial quality by modulating the spatial components at the Fourier-plane, using a pinhole of appropriate size or recently by a nonlinear process. Modulation of the beam in the Fourier-plane allows however a simultaneous spatial and temporal filtering. By the use of a "conjugate" pinhole arrangement before and after the nonlinear spatial selector, intensity dependent transmission is obtained: the low intensity part is efficiently suppressed. Numerical calculations predict practical operation for both amplitude and phase modulation at the Fourier-plane. In the preferred latter case the experimental observations are in good agreement with the theory, demonstrating >40% throughput.

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Plasma mirror and temperature evolution for short pulse KrF lasers

Cited by 12 publications

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Plasma Mirrors for Cleaning Laser Pulses from the Infrared to the Ultraviolet

Plasma Mirrors for Cleaning Laser Pulses from the Infrared to the Ultraviolet

Reflectivity and spectral shift from laser plasmas generated by high-contrast, high-intensity KrF laser pulses

Improvement of the spatial and temporal contrast of short-pulse KrF laser beams

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