Correlation between birefringence and absorption mapping in large-size Sapphire substrates for gravitational-wave interferometry.

ABSTRACT: In high-sensitive laser interferometers, such as the gravitational-wave detector KAGRA, ultra-high-quality mirrors are essential. In the case of KAGRA, where cavity mirrors are cooled down to 20 K, large-size Sapphire crystals are used as the substrate for the main mirrors to achieve both a good optical quality (i.e., low absorption and uniform refractive index) and optimized thermal behavior under cryogenic temperatures. To implement the very tight optical specifications required by this demanding application, it is mandatory to test the optical homogeneity of different substrates. In order to characterize refractive-index inhomogeneities of large-size uniaxial samples such as the KAGRA Sapphire test masses, we developed a dedicated setup, allowing to resolve birefringence changes with a

SUBMITTER: Zeidler S 

PROVIDER: S-EPMC10696018 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature