第十五届全国表面工程青年学术会议

This study focused on the design, preparation and testing of the HfO₂/SiO₂ total reflection film, which was designed based on the Fresnel formula and the multilayered film interference theory and was optimized by TFCalc. By optimizing the substrate temperature during the plasma-assisted electron beam evaporation deposition process, the number of layers of the film and layer thickness values were consistent with the theoretical values with an error of about ±0.2 µm, which meets the requirements of the designed film. The surfaces of all multilayered films are very smooth (Ra<1 nm), the layers are well organized, and the layer interface is very clean without cracks or defects. The spectrophotometer spectra show that the reflectance rates of the HfO₂/SiO₂ total reflection film at 1064 nm are all close to 100 %, and exhibit strong suppression capabilities. Meanwhile, the Laser-Induced Damage Threshold of the HfO₂/SiO₂ total reflection film increased by 36.6 %, raising it from the initial value of 11.2 J/cm² to 15.3 J/cm². The improved Laser-Induced Damage Threshold was proved to be attributed to the significant changes in the crystallinity and roughness of the film, which altered the crystal structure and density by the substrate temperature. It is important to note that the discovery of HfO₂/SiO₂ total reflection film with lower surface roughness is also conducive to enhancing the Laser-Induced Damage Threshold of the films, enabling their application in high-power laser optical systems.

HfO2/SiO2 total reflection film; Laser-induced damage threshold; Substrate temperature; plasma-assisted electron beam evaporation.