The relative roles of avalanche multiplication and multiphoton absorption in laser-induced damage of dielectrics

Abstract

The optical electric field strengths associated with pulsed laser exposures needed to produce conduction electron densities of 1018/cm3 in several direct-gap alkali halides are calculated using three different models: a simplified avalanche model, the Keldysh formulation of multiphoton ionization, and a combination of the two. Numerical calculations are performed for crystalline NaCl, KCl, KBr, NaF, LiF, and CaFz at wavelengths of 1.064,0.694,0532, and 0.355 pm, for nanosecond and picosecond pulse durations. The results

Wavelength dependence of femtosecond laser-induced breakdown in water and implications for laser surgery

“…Besides the pulse duration dependence, also the wavelength dependence of the breakdown threshold, I th (λ), contains valuable information on the breakdown dynamics [44].…”

Effect of SiO 2 protective layer on the femtosecond laser-induced damage of HfO 2 /SiO 2 multilayer high-reflective coatings

“…That is, the SiO 2 protective layer decreased the damage threshold of HfO 2 /SiO 2 Table 1 List of parameters for HfO 2 and SiO 2 used in the theoretical calculation The values for t K , t L and hv p were obtained from Ref. [19]. The values for m * , m à e and m à h were obtained from Ref.…”

Energy transmissivity of high-power nanosecond laser pulse focused on glass

“…Stuart [6] found that the basic reason for the glass' absorption of energy is bremsstrahlung effect, which is induced by the free electron's absorption of laser energy. High intensity free electron will be given rise to by nonlinear ionization when glass is exposed to high-power laser [7][8][9].…”