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…