Measurement of birefringence of low-loss, high-reflectance coating of m-axis sapphire
- Resource Type
- Authors
- Martin M. Fejer; William Kells; Jordan Camp; Eric K. Gustafson
- Source
- Applied optics. 40(22)
- Subject
- Birefringence
Materials science
Gravitational-wave observatory
business.industry
Materials Science (miscellaneous)
Detector
engineering.material
Laser
Polarization (waves)
Industrial and Manufacturing Engineering
law.invention
Interferometry
Optics
Coating
law
engineering
Sapphire
Optoelectronics
Business and International Management
business
- Language
- ISSN
- 1559-128X
The birefringence of a low-loss, high-reflectance coating applied to an 8-cm-diameter sapphire crystal grown in the m-axis direction has been mapped. By monitoring the transmission of a high-finesse Fabry-Perot cavity as a function of the polarization of the input light, we find an upper limit for the magnitude of the birefringence of 2.5 x 10(-4) rad and an upper limit in the variation in direction of the birefringence of 10 deg. These values are sufficiently small to allow consideration of m-axis sapphire as a substrate material for the optics of the advanced detector at the Laser Interferometer Gravitational Wave Observatory.