Point defects in IBS coating for very low loss mirrors

TL;DR

This paper investigates point defects in IBS coatings used in high-precision mirrors, analyzing their formation, behavior under different conditions, and reduction through annealing to improve mirror performance.

Contribution

It provides the first detailed study of point-like scatterers in IBS coatings, exploring how material type and thickness influence defect formation and how annealing mitigates these defects.

Findings

Defects vary with coating material and thickness.

Annealing reduces defect density.

Insights into defect formation mechanisms.

Abstract

High reflective coatings are used in many physics experiments. Despite the high quality of the opticalcoating, the performances of the mirrors is altered by the scattered light induced by micrometers sizedefects in the coating layers. The topic of this paper is the study of the point-like scatterers present in thespecific coating of the mirrors used in state of the art, high sensitivity optical experiments. We studied thebehavior of the materials according to different thicknesses, and how the defects change after annealing.To our knowledge, this is a first insight into the formation of such defects for different materials andthickness and how this is reduced when samples are annealed.