Physics of femtosecond-to-picosecond optical pulses and their interaction with matter. Generation: passive mode-locking (saturable absorbers, SESAMs), Kerr-lens mode-locking (Ti:sapphire, Yb:KYW), chirped-pulse amplification…
ultrafast-physics
Passive mode-locking via saturable absorber / SESAM
Passive mode-locking uses a saturable absorber (solid dye, semiconductor saturable absorber mirror SESAM, graphene, carbon-nanotube) with…
Kerr-lens mode-locking: self-focusing via n₂·I in Ti:sapphire
Spence-Kean-Sibbett 1991 Kerr-lens mode-locking (KLM): the intensity-dependent refractive index n(I) = n₀ + n₂·I of the gain crystal…
Optical soliton: anomalous GVD balances self-phase modulation
Hasegawa-Tappert 1973 / Mollenauer-Stolen-Gordon 1980 optical soliton in a single-mode fibre: the cubic nonlinear Schrödinger equation i∂_z…
Fourier TBP: Gaussian Δτ·Δν = 2 ln 2/π ≈ 0.441 (transform-limited)
Fourier-transform duality pins a minimum time-bandwidth product (TBP) for any pulse with a specified temporal-intensity profile. For an…
SHG phase-matching: η ∝ sinc²(ΔkL/2); coherence length L_c = π/|Δk|
Franken-Hill-Peters-Weinreich 1961 second-harmonic generation (SHG) in a nonlinear crystal: in the slowly-varying-envelope +…
GVD broadening of chirp-free Gaussian: τ_out = τ_in√(1 + (L/L_D)²)
Agrawal 2019 Nonlinear Fiber Optics §3: an initially unchirped Gaussian pulse of 1/e-intensity half-width τ_in propagating through a linear…
NLSE bright soliton u = η sech(ηx) e^{iη²t/2}; inverse scattering → 1 discrete eigenvalue
Nonlinear-Schrödinger-equation (NLSE) bright-soliton framework — the canonical nonlinear-wave structure of optical-fibre telecommunications…
Kramers–Kronig dispersion: χ'(ω) + iχ''(ω); residue-theorem contour closure
Kramers-Kronig dispersion-relation framework — the canonical causality-enforcing link between the real (dispersive) and imaginary…
Gires–Tournois: r(ω) = (r₁ − e^{−iφ})/(1 − r₁ e^{−iφ}); |r| = 1, Möbius-phase nonlinear
Gires-Tournois-interferometer framework — the canonical chirped-mirror / phase-only optical element engineering femtosecond-pulse…
NLSE 1-soliton: Q = 2η, T = η³/3, V = −2η³/3, H = −η³/3 (exact integrability pins)
Sympy-exact symbolic witness of the NLSE bright-soliton integrability invariants — the canonical conservation laws of Zakharov-Shabat…
KK residues: χ''(ω) Lorentz poles at ω₀ ± iγ → residues ∓i/2 (causality)
Sympy-exact symbolic witness of the Kramers-Kronig contour-residue structure for a canonical Lorentzian absorption profile. Setup: ω, ω₀,…
GT: |r|²=1; arg r = −2·atan(((1+r₁)/(1−r₁))·tan(φ/2)); dispersive Möbius-rational ∂_φ arg
Sympy-exact symbolic witness of the Gires-Tournois Möbius-transformation reflectance and its dispersive phase structure. Setup: r₁ ∈ (0,1)…
fs-chemistry (Zewail 1980s)
Zewail 1980s (Nobel 1999) fs-pump-probe of transition states; modern attochemistry + electron-vs-nuclear-motion separation.
KLM (Spence-Sibbett-Sleat 1991)
Spence-Sibbett-Sleat 1991 Kerr-lens mode-locking Ti:Sapphire; modern fs lasers commercial; basis of attosecond-physics.
Strong-field ionization
Keldysh 1965 + Faisal-Reiss tunneling vs multiphoton; modern coltrap + ion-momentum-imaging Cooper-cusp + RABBITT.
XFEL (LCLS 2009)
SASE-XFEL theory Bonifacio 1984 + LCLS 2009 first hard-X-ray FEL; modern European-XFEL + LCLS-II + serial-femtosecond crystallography.
OPA (Cerullo 2003)
Cerullo-De Silvestri 2003 NOPA few-cycle visible OPA; modern broadband mid-IR / few-cycle THz OPA pumping; ultrafast spectroscopy.
Streaking (Itatani 2002)
Itatani 2002 attosecond-streaking; modern reconstruction-of-attosecond-bursts; fundamental tool in attophysics.
Zewail femtochemistry detail (Nobel 1999)
A Zewail 1988 (Nobel 1999) ICN→I+CN 200 fs probe; modern modern foundational text + 2024 attoclock + UED 4D-imaging chemical-dynamics.
Kerr-lens mode-locking (Spence 1991)
D Spence-W Sibbett 1991 self-mode-locking-Ti:sapphire; modern modern foundational + 5-fs-Krausz 1997 + 2024 sub-cycle 4-cycle…
Keldysh (1965)
L Keldysh 1965 strong-field-ionization γ_K = ω√(2I_p)/eE; modern modern foundational text + tunneling/multiphoton transition + 2024…
UED (Zewail 2010)
A Zewail 2010 ultrafast-electron-diffraction; modern modern foundational + MeV-UED + 2024 MeV-cryo-UED protein-dynamics 100 fs.
Optical rectification (Bass 1962)
M Bass 1962 + Mourou-Auston 1985 THz-pulse-generation; modern modern foundational text + 2024 strong-field THz-induced field-emission.
Pump-probe (Norrish-Porter 1949)
R Norrish-G Porter 1949 + M Eigen 1954 (Nobel 1967) flash-photolysis pump-probe; modern modern foundational text + sub-fs probes + 2024…