Spence-Kean-Sibbett 1991 Kerr-lens mode-locking (KLM): the intensity-dependent refractive index n(I) = n₀ + n₂·I of the gain crystal (Ti:sapphire n₂ ≈ 3·10⁻²⁰ m²/W) causes high-intensity radial beam profiles to self-focus — the beam waist…
Spence-Kean-Sibbett 1991 Kerr-lens mode-locking (KLM): the intensity-dependent refractive index n(I) = n₀ + n₂·I of the gain crystal (Ti:sapphire n₂ ≈ 3·10⁻²⁰ m²/W) causes high-intensity radial beam profiles to self-focus — the beam waist…