DPG Phi
Verhandlungen
Verhandlungen
DPG

Berlin 2014 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

GR: Fachverband Gravitation und Relativitätstheorie

GR 6: Gravitational waves

GR 6.2: Talk

Monday, March 17, 2014, 16:50–17:10, SPA SR220

Birefringence Measurements of Laser Mirrors from Crystaline Silicon — •Christoph Krüger, Roman Schnabel, and Harald Lück — Albert-Einstein-Institut, Institut für Gravitationsphysik Leibniz Universität Hannover

Laser interferometric gravitational wave detectors (GWD) are using high light powers in order to achieve a high sensitivity of measurement. Future detectors of the so called 3rd generation - like the Einstein Telescope (ET) - will furthermore make use of optics cooled to cryogenic temperatures to improve the sensitivity. The current fused silica optics used at room temperature are not suited for operation at cryogenic temperatures, hence alternative optical materials have to be investigated. The baseline design of the Einstein Telescope foresees silicon as test-mass material.

The optical birefringence of a test-mass, however, may limit the GWD or cause additional optic losses. Transmitting light through a medium with birefringence can cause conversion of light from one polarization state into the other one and act as an undesired optical loss channel.

We developed a measurement technique with a sensitivity for birefringence n1n2 = Δ n as low as 10−8. The talk presents the measurements of silicon birefringence obtained from different mono-crystalline silicon samples and its dependence on experimental parameters such as mechanical load, orientation and suspension of the crystals.

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2014 > Berlin