Laser-induced damage threshold of ZrO2 thin films prepared at different oxygen partial pressures by electron-beam evaporation

Abstract

ZrO 2 films were deposited by electron-beam evaporation with the oxygen partial pressure varying from 3 ϫ 10 −3 Pa to 11ϫ 10 −3 Pa. The phase structure of the samples was characterized by x-ray diffraction (XRD). The thermal absorption of the films was measured by the surface thermal lensing technique. A spectrophotometer was employed to measure the refractive indices of the samples. The laser-induced damage threshold (LIDT) was assessed using a 1064 nm Nd: yttritium-aluminumgarnet pulsed laser at pulse width of 12 ns. The influence of oxygen partial pressure on the microstructure and LIDT of ZrO 2 films was investigated. XRD data revealed that the films changed from polycrystalline to amorphous as the oxygen partial pressure increased. The variation of refractive index at 550 nm wavelength indicated that the packing density of the films decreased gradually with increasing oxygen partial pressure. The absorptance of the samples decreased monotonically from 125.2 to 84.5 ppm with increasing oxygen partial pressure. The damage threshold values increased from 18.5 to 26.7 J / cm 2 for oxygen partial pressures varying from 3 ϫ 10 −3 Pa to 9 ϫ 10 −3 Pa, but decreased to 17.3 J / cm 2 in the case of 11ϫ 10 −3 Pa.

Comparison of ion post treatment and laser conditioning of thin films

“…In 2004, the first paper about using ion posttreatment to improve LIDT of ZrO 2 thin films was reported. The result shows that LIDT was improved nearly 45% by this technique 4 . The schematic of ion posttreatment of thin film is shown in figure 3.…”

Properties of HfO2 thin films prepared by dual-ion-beam reactive sputtering

“…The surface thermal lensing (STL) technique, which permits to measure very low levels of absorptance, was employed in measuring the samples absorptance in our investigation. The experimental setup and theory about this technique are shown elsewhere [14,15]. The absorptance of the as-grown sample and annealed under 200 1C in atmosphere for 2 h were measured, respectively.…”

Microstructure and 355 nm Laser-Induced Damage Characteristics of Al<sub>2</sub>O<sub>3</sub> Films Irradiated with Oxygen Plasma under Different Energy

“…Laser was irradiated in the direction of normal incidence of the sample surface. The testing system could see in our previous research work [22]. Laser-induced damage morphologies were characterized and analyzed under a Leica polarizing microscope.…”