Physics of light pulses and dynamics on the attosecond (1 as = 10⁻¹⁸ s) time-scale. 2023 Nobel Prize (L'Huillier, Krausz, Agostini) recognised the high-harmonic-generation (HHG) pathway to attosecond extreme-UV / soft-X-ray pulses via the…
attosecond-physics
HHG three-step model (Corkum 1993): ionise → propagate → recombine
Corkum 1993 three-step (simple-man) model of high-harmonic generation: step 1 — a strong linearly-polarised infrared laser field E(t) = E₀…
Attosecond streak camera: momentum shift Δp(τ) = e·A_IR(τ)
Itatani-Quéré 2002 / Kienberger-Goulielmakis 2004 attosecond streak camera: a synchronised infrared streaking field A_IR(τ) maps the…
CPA (Strickland-Mourou 1985, 2018 Nobel): stretch → amplify → compress
Strickland-Mourou 1985 chirped-pulse amplification (2018 Nobel Prize): stretch a short seed pulse in time by imposing a large…
Keldysh parameter γ = √(I_p/(2U_p)): multiphoton ↔ tunnel boundary
Keldysh 1965 adiabaticity parameter separating the two limiting ionisation regimes under a strong laser field: γ = √(I_p/(2U_p)) = ω·√(2m_e…
HHG cutoff (Corkum 1993): ℏω_max = I_p + 3.17·U_p
Corkum 1993 high-harmonic-generation cutoff: the highest coherent harmonic photon energy that can be emitted by the three-step process is…
Ponderomotive energy: U_p = e²E₀²/(4m_eω²); practical U_p[eV] ≈ 9.33·10⁻¹⁴·I[W/cm²]·λ²[μm²]
Ponderomotive energy U_p is the cycle-averaged kinetic energy of a free electron oscillating (quivering) in a monochromatic…
Strong-field-approximation saddle-point: ∂_t S(p,t) = 0; Hamilton–Jacobi action
Strong-field-approximation (SFA) saddle-point framework — the canonical semiclassical primitive for high-harmonic-generation amplitude…
RABBITT sideband S_{2q} = A + B·cos(Δφ + 2ω_IR τ_d); Bessel-function amplitudes
RABBITT (reconstruction of attosecond beating by interference of two-photon transitions) framework — the canonical interferometric method…
Gaussian wavepacket spreading: σ(t) = √(ℏ²t² + 4m²σ₀⁴)/(2mσ₀); heat-like diffusion
Gaussian-wavepacket free-propagation framework — the canonical time-domain primitive for ultrafast electron and atom wavepacket evolution…
HHG cutoff E_max = I_p + 317·U_p/100 via SFA saddle-point Hamilton–Jacobi action
Sympy-exact symbolic witness of the SFA saddle-point high-harmonic cutoff E_max = I_p + 3.17·U_p. Setup: I_p (ionisation potential), U_p…
RABBITT: S_{2q} = A + B·cos(Δφ + 2ωτ); J₀(0) = 1; J₁(z) ≈ z/2 weak-field
Sympy-exact symbolic witness of the RABBITT sideband oscillation and its Bessel-function amplitude structure. Setup: A_const, B_amp…
Wavepacket σ(t) = √(ℏ²t² + 4m²σ₀⁴)/(2mσ₀); σ(0) = σ₀; lim_{t→∞} dσ/dt = ℏ/(2mσ₀)
Sympy-exact symbolic witness of Gaussian-wavepacket spreading dynamics — the canonical attosecond benchmark for free-particle evolution. …
HHG three-step (Corkum 1993)
P Corkum 1993 + Lewenstein 1994 three-step model: tunnel-ionization, free-electron acceleration, recombination -> high-harmonic photon up…
Isolated attosecond pulse (Krausz 2001)
Krausz-Brabec 2001 + Hentschel 2001 first 650-as XUV pulse from few-cycle IR; gating techniques (amplitude/polarization) isolate single…
RABBITT (Paul 2001 / Muller 2002)
Paul 2001 + Muller 2002 RABBITT: cross-correlation between IR + XUV harmonics gives ~10 as photoionization-time-delay measurement;…
Eisenbud-Wigner-Smith delay
Wigner 1955 + Eisenbud 1948 photoionization-time-delay tau_EWS = d phi/d E; measured ~21 as Ne 2s-2p delay (Schultze 2010 Science).
Charge migration (Cederbaum 1999)
Cederbaum-Zobeley 1999 attosecond charge-migration in molecules: prompt sub-fs hole-dynamics independent of nuclear motion; Calegari 2014…
Keldysh-Faisal-Reiss SFA
Keldysh 1965 + Faisal 1973 + Reiss 1980 strong-field approximation: gamma_K = sqrt(I_p/2 U_p); tunneling regime gamma << 1 vs multiphoton…
First attopulse (Hentschel 2001)
M Hentschel-F Krausz 2001 + Drescher 2002 first attosecond-pulse 650 as; modern modern foundational + 2023 Krausz-L'Huillier-Agostini Nobel…
Train (Paul 2001)
P-M Paul 2001 attosecond-train Photoionization 250 as; modern modern foundational text + RABBITT P-M Paul + 2024 isolated-attopulse…
HHG model (Corkum 1993)
P Corkum 1993 three-step-recollision-HHG; modern modern foundational + Lewenstein 1994 quantum + 2024 ML-HHG-spectroscopy.
Wigner delay (Eisenbud-Wigner 1955)
E Eisenbud-E Wigner 1955 wave-packet-delay; modern modern foundational + Schultze 2010 attoclock + Pazourek-Burgdörfer 2015 timing.
Streak camera (Itatani 2002)
J Itatani 2002 attosecond-streak-camera; modern modern foundational + 2024 Krausz attoEM + 2023 Krausz Agostini L'Huillier Nobel attosecond.
Water-window HHG (Popmintchev 2012)
T Popmintchev-Murnane-Kapteyn 2012 mid-IR keV HHG; modern modern foundational + biological-imaging C-K-edge water-window 2024.