The development of ultra-intense and ultra-short light sources is currently a subject of intense research driven by the discovery of novel phenomena in the realm of relativistic optics,such as the production of ultraf...The development of ultra-intense and ultra-short light sources is currently a subject of intense research driven by the discovery of novel phenomena in the realm of relativistic optics,such as the production of ultrafast energetic particle and radiation beams for applications.It has been a long-standing challenge to unite two hitherto distinct classes of light sources:those achieving relativistic intensity and those with pulse durations approaching a single light cycle.While the former class traditionally involves large-scale amplification chains,the latter class places high demand on the spatiotemporal control of the electromagnetic laser field.Here,we present a light source producing waveformcontrolled 1.5-cycle pulses with a 719 nm central wavelength that can be focused to relativistic intensity at a 1 kHz repetition rate based on nonlinear post-compression in a long hollow-core fiber.The unique capabilities of this source allow us to observe the first experimental indications of light waveform effects in laser wakefield acceleration of relativistic energy electrons.展开更多
We report evidence for the first generation of XUV spectra from relativistic surface high-harmonic generation(SHHG)on plasma mirrors at a kilohertz repetition rate,emitted simultaneously with energetic electrons.SHHG ...We report evidence for the first generation of XUV spectra from relativistic surface high-harmonic generation(SHHG)on plasma mirrors at a kilohertz repetition rate,emitted simultaneously with energetic electrons.SHHG spectra and electron angular distributions are measured as a function of the experimentally controlled plasma density gradient scale length Lg for three increasingly short and intense driving pulses:24 fs and a0=1:1,8 fs and a0=1:6,and finally 4 fs and a0≈2:1,where a0 is the peak vector potential normalized by mec/e with the elementary charge e,the electron rest mass me,and the vacuum light velocity c.For all driver pulses,we observe correlated relativistic SHHG and electron emission in the range Lg∈½λ/20,λ/4,with an optimum gradient scale length of Lg≈λ/10.This universal optimal Lg-range is rationalized by deriving a direct intensity-independent link between the scale length Lg and an effective similarity parameter for relativistic laser-plasma interactions.展开更多
基金supported by Agence Nationale pour la Recherche(ANR-11-EQPX-005-ATTOLAB,ANR-14-CE32-0011-03 APERO)Laboratoire d’Excellence Physique:Atomes Lumiere Matiere(LabEx PALM)overseen by the Agence Nationale pour la Recherche as part of the Investissements d’Avenir program(ANR-10-LABX-0039)+2 种基金European Research Council(ERC Starting Grant FEMTOELEC 306708,ERC Advanced Grant ExCoMet 694596)LASERLABEUROPE(H2020-EU.1.4.1.2.grant agreement ID 654148)Region Ile-de-France(SESAME 2012-ATTOLITE).
文摘The development of ultra-intense and ultra-short light sources is currently a subject of intense research driven by the discovery of novel phenomena in the realm of relativistic optics,such as the production of ultrafast energetic particle and radiation beams for applications.It has been a long-standing challenge to unite two hitherto distinct classes of light sources:those achieving relativistic intensity and those with pulse durations approaching a single light cycle.While the former class traditionally involves large-scale amplification chains,the latter class places high demand on the spatiotemporal control of the electromagnetic laser field.Here,we present a light source producing waveformcontrolled 1.5-cycle pulses with a 719 nm central wavelength that can be focused to relativistic intensity at a 1 kHz repetition rate based on nonlinear post-compression in a long hollow-core fiber.The unique capabilities of this source allow us to observe the first experimental indications of light waveform effects in laser wakefield acceleration of relativistic energy electrons.
基金supported by the Agence Nationale pour la Recherche(ANR-11-EQPX-005-ATTOLAB and ANR-14-CE32-0011-03 APERO)Investissements d’Avenir Program LabEx PALM(ANR-10-LABX-0039-PALM)+2 种基金European Research Council(ERC FEMTOELEC 306708 and ERC ExCoMet 694596)Laserlab-Europe(H2020-EU.1.4.1.2.grant agreement ID 654148)Région Ile-de-France(SESAME 2012-ATTOLITE).
文摘We report evidence for the first generation of XUV spectra from relativistic surface high-harmonic generation(SHHG)on plasma mirrors at a kilohertz repetition rate,emitted simultaneously with energetic electrons.SHHG spectra and electron angular distributions are measured as a function of the experimentally controlled plasma density gradient scale length Lg for three increasingly short and intense driving pulses:24 fs and a0=1:1,8 fs and a0=1:6,and finally 4 fs and a0≈2:1,where a0 is the peak vector potential normalized by mec/e with the elementary charge e,the electron rest mass me,and the vacuum light velocity c.For all driver pulses,we observe correlated relativistic SHHG and electron emission in the range Lg∈½λ/20,λ/4,with an optimum gradient scale length of Lg≈λ/10.This universal optimal Lg-range is rationalized by deriving a direct intensity-independent link between the scale length Lg and an effective similarity parameter for relativistic laser-plasma interactions.