Publications by authors named "E Lavastre"
Article Synopsis
- High-energy laser facilities need specialized multilayer coatings on large surfaces, requiring strict control over deposition parameters to achieve desired optical and mechanical qualities.
- The study expands the understanding of how relative humidity affects these coatings, causing shifts in their optical spectra, which are usually limited to a narrow wavelength range.
- Validation of the spectral shift method involved comparing the effects of humidity on single layers with simulated changes due to thickness or refractive index, revealing that humidity primarily influences the refractive index, with SiO being more responsive than HfO.
Article Synopsis
- The performance of petawatt-class lasers is hindered by damage to optical components, particularly pulse compression gratings, which can be improved by using multilayer dielectric (MLD) gratings that offer high efficiency and resistance to damage.
- Research indicates that the etching profile of these gratings affects the electric field distribution, influencing their resistance to laser damage.
- This study investigates how the design of the multilayer stack affects the electric field intensity and laser-induced damage threshold, demonstrating that optimized multilayer designs can enhance the durability of MLD gratings in high-power laser applications.
PETAL (Petawatt Aquitaine Laser) is an ultrahigh-power laser dedicated to academic research that delivers sub-picosecond pulses. One of the major issues of these facilities is the laser damage on optical components located at the final stage. Transport mirrors of the PETAL facility are illuminated under different polarization directions.
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- High-power laser facilities face limitations in performance due to laser-induced damage to optical components, which affects their lifespan.
- Researchers conducted experiments on different multilayer dielectric mirror designs to explore whether improving the laser damage initiation threshold also minimizes damage growth.
- Findings showed that optimized mirror designs effectively increased damage thresholds and reduced growth rates, supported by numerical models that matched experimental results.
Laser-induced damage growth has often been studied with Gaussian beams in the sub-picosecond regime. However, beams generated by high-power laser facilities do not feature Gaussian profiles, a property that raises questions concerning the reliability of off-line laser-induced damage measurements. Here, we compare laser-induced damage growth dynamics as a function of beam profiles.
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