Next generation highly resistant mirrors featuring all-silica layers

Abstract

A principal possibility to overcome fundamental (intrinsic) limit of pure optical materials laser light resistance is investigated by designing artificial materials with desired optical properties. We explore the suitability of high band-gap ultra-low refractive index material (n less than 1.38 at 550 nm) in the context of highly reflective coatings with enhanced optical resistance. The new generation all-silica (porous/nonporous) SiO2 thin film mirror with 99% reflectivity was prepared by glancing angle deposition (GLAD). Its damage performance was directly compared with state of the art hafnia/silica coating produced by Ion-Beam-Sputtering. Laser-Induced Damage Thresholds (LIDT) of both coatings were measured in nanosecond regime at 355 nm wavelength. Novel approach indicates the potential for coating to withstand laser fluence of at least 65 J/cm2 without reaching intrinsic threshold value. Reported concept can be expanded to virtually any design thus opening a new way of next generation thin film production well suited for high power laser applications.

Nonlinear pulse compression based on a gas-filled multipass cell

“…Compared to capillaries, gas-filled multipass cells allow very efficient compression, longer propagation distances, and larger beam sizes. Moreover, progress in mirror coating technologies, with a damage threshold increasing over the years [19] and dispersion management capabilities over broader bandwidths [20], suggests that this technique could be used advantageously in a large number of ultrafast laser systems. The overall agreement between our experimental data with a 3D numerical model describing the propagation is excellent, including the absence of spatio-temporal couplings.…”

Anisotropy of 3D Columnar Coatings in Mid-Infrared Spectral Range

“…It becomes possible to make strongly birefringent thin films by GLAD using optically isotropic Si and SiO 2 materials [6]. It was recently demonstrated that such films have larger visible and near-infrared (near-IR) laser damage thresholds in J/cm 2 compared to polished surfaces or coatings made out of the two different materials [7]. GLAD deposited thin films can also act as an antireflection coating [8,9].…”

Anisotropy of 3D Columnar Coatings in Mid-Infrared Spectral Range

“…It becomes possible to make strongly birefringent thin films by GLAD using optically isotropic Si and SiO 2 materials [6]. It was recently demonstrated that such films have larger visible and near-infrared (near-IR) laser damage thresholds in J/cm 2 compared to polished surfaces or coatings made out of the two different materials [7]. GLAD deposited thin films can also act as an antireflection coating [8,9].…”