Abstract
Crystalline silicon has been proposed as a new test mass material in third generation gravitational wave detectors such as the Einstein telescope (ET). Birefringence can reduce the interferometric contrast and can produce dynamical disturbances in interferometers. In this work we use the method of polarization-dependent resonance-frequency analysis of Fabry–Perot-cavities containing silicon as a birefringent medium. Our measurements show a birefringence of silicon along the (111) axis of the order of at a laser wavelength of 1550 nm and room temperature. A model is presented that explains the results of different settings of our measurements as a superposition of elastic strains caused by external stresses in the sample and plastic strains possibly generated during the production process. An application of our theory on the proposed ET test mass geometry suggests no critical effect on birefringence due to elastic strains.
Highlights
The initial as well as the advanced version of gravitational wave (GW) detectors, which are currently being installed, such as aLIGO and advanced Virgo, use suspended fused silica optics as test masses [1, 2]
Making further use of the equations given in [13], we can derive an upper limit for the acceptable birefringence assuming that the axes of the indices of refraction of silicon are oriented at an angle of π/4 to the linear polarization of the laser light used in the GW detector
In this paper we present a sensitive method for the experimental characterization of birefringence in optical materials
Summary
The initial as well as the advanced version of gravitational wave (GW) detectors, which are currently being installed, such as aLIGO and advanced Virgo, use suspended fused silica optics as test masses [1, 2]. These observatories are set up as dual-recycled cavity-enhanced Michelson-type laser interferometers with a kilometer-scale baseline and are operated at room temperature. In this paper we investigate birefringence and its effects in silicon test masses at room temperature. Based on our results we estimate the expected birefringence in the test-masses of ET
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
