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…