Angle Resolved Backscatter of HfO_2/SiO_2 Multilayer Mirror at 1064 nm

摘要

Angle resolved light scattering was measured at 1064 nm on an HfO_2/SiO_2 multilayer mirror deposited via modified plasma ion-assisted deposition. A total backscatter of approximately 4.0×10~(-4) was calculated by integrating the angle resolved scattering curves over the backscattering hemisphere. In this way, also the an integrated near angle backscatter of 1.2× 10~(-4) was derived for angles from 0° to 2° and an integrated near angle scatter of 6×10~(-5) was determined in the most critical range from 0.5° to 2°. 12% of the total backscatter originated from the near angle region between 2° and 4°. 36%, 62%, 76% and 86% of the total backscatter were created from 2° to 10°, 20 °, 30 ° and 40 °, respectively. Good agreement was obtained for the total backscatter values calculated from the ARS measurements and the top-surface roughness derived by AFM measurements.