The generation of third harmonic radiation (THG) is required for many pulsed solid-state laser applications in industry
and science. In this contribution, the coatings for two necessary optical components, dichroic mirrors and nonlinear
optical (NLO) crystals are in the focus of investigation. Because of the high bulk damage threshold lithium triborate
(LBO) crystals are applied for this study. HfO<sub>2</sub>/SiO<sub>2</sub> mixtures are employed as high refractive index material to improve
the power handling capability of the multilayers. All coatings are produced by ion beam sputtering (IBS) using a zone
target assembly for the deposition of material mixtures. The atomic composition and the oxidation ratio of different
HfO<sub>2</sub>/SiO<sub>2</sub> mixtures are analyzed by X-ray photoelectron spectroscopy (XPS). The influence of different deposition
temperatures and post annealing on the optical properties and the amorphous micro structure of the films is investigated
by UV/Vis/NIR spectroscopy and X-ray diffraction (XRD). The laser induced damage thresholds at 355 nm wavelength
for nanosecond pulse durations are measured in a 10,000on1 experiment according with the standard ISO21254.
Furthermore, the optical components are tested under real application conditions.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Mathias Mende ; Lars O. Jensen ; Henrik Ehlers ; Stefan Bruns ; Michael Vergöhl, et al.
"Applying hafnia mixtures to enhance the laser-induced damage threshold of coatings for third-harmonic generation optics", Proc. SPIE 8530, Laser-Induced Damage in Optical Materials: 2012, 85300W (December 6, 2012); doi:10.1117/12.971225; http://dx.doi.org/10.1117/12.971225