TDDFT Simulations Show TiO2 Mirrors Lose Reflectance Above 10^13 W/cm²
First-principles TDDFT modeling demonstrates that TiO2 dielectric mirrors suffer measurable reflectance drops at intensities typical of high-power femtosecond lasers. The effect arises from multiphoton-generated carriers whose density depends on crystal phase. Preprint results provide microscopic guidance for mirror optimization but await experimental confirmation.
Next steps include embedding the computed nonlinear susceptibilities into ray-tracing codes used by laser-facility designers and testing the predictions against pump-probe experiments on actual TiO2 coatings. If validated, the data could guide substitution of lower-nonlinearity phases or protective capping layers.
Uemoto group: Within 18 months, at least one high-power laser facility will report >5% reflectance drop in TiO2 mirrors at 10^13 W/cm², matching the simulated threshold.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2608.25129)
- [2]Supporting Source(https://doi.org/10.1103/PhysRevB.102.045201)