Mainz 2017 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 5: Precision Measurements and Metrology: Gravity
Q 5.6: Talk
Monday, March 6, 2017, 16:00–16:15, P 104
Experiment to investigate collinear back-reflections of optical components — •Michael Winter1, Oliver Gerberding2, Katharina-Sophie Isleif1, Daniel Penkert2, Stefan Ast2, Lea Bischof1, Gerhard Heinzel2, Jens Reiche2, and Karsten Danzmann1,2 — 1Albert Einstein Institute Hannover, Leibniz Universität Hannover — 2Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
The Laser Interferometer Space Antenna (LISA) is a planned space-based gravitational wave detector with arm lengths of some million kilometres. Due to orbital dynamics the angle between the arms changes. Thus an adaptable link (backlink) between the two optical benches inside each spacecraft is required. Previous experiments have shown that a fiber solution is limited by collinear ghost beams. Additional optical components can be used to avoid them or make them irrelevant, e.g. Faraday Isolators or AOMs. Collinear back-reflections of the components are designated to be the new limiting factors.
To investigate these back-reflections a simple cavity-like setup is used, whereby the component to be examined forms one half of an ultra-low finesse cavity. Deep Frequency Modulation (DFM) interferometry is then applied to generate self-interference at AC-frequencies for a quasi heterodyne detection.
This talk will give an overview of the operating principle and the characterization of the setup. Thereby the focus lies on reconciling theory and experiment to connect obtained signal and power reflectivity of the device-under-test, revealing collinear back-reflection properties.