Modeling ultrafast laser excitation of fused silica with a hybrid Lorentz–Drude dielectric response and density-dependent two-temperature model

Description

Daniel Metzner and co-authors build in 2026 a physics model of what an ultrafast laser pulse does inside fused silica, the glass of lenses and optical fibres. A pulse lasting trillionths of a second excites electrons faster than the lattice can respond, and older models treat the optics and the heating as separate stories. Their framework welds the two into one coupled description.

Optical behaviour follows a hybrid formula covering bound, localised, and freed electrons, while a two-temperature thermal model uses material parameters that shift with electron density, drawn from first-principles calculations. Checked against measured ablation craters and thresholds for femtosecond and picosecond pulses, the model matched depths and diameters reasonably in the fast regime. It also showed that measurable material removal can begin below the model's own explosion criterion, especially for longer pulses, a useful caution for laser machining.

Catalog record

Source: https://europepmc.org/article/MED/PMC13408711