Hannover 2010 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 68: Laser Applications: Optical Measurement Technology II
Q 68.6: Talk
Friday, March 12, 2010, 15:15–15:30, F 342
Development of RF Low Noise Quadrant Photo Detectors for Optical Translation and Tilt Metrology — •Steffen Wälde1,2, Martin Maurer1,2, Martin Gohlke1,3, Thilo Schuldt2,3, Ulrich Johann1, Dennis Weise1, and Claus Braxmaier2 — 1EADS Astrium — 2HTWG Konstanz — 3Humboldt-Universität zu Berlin
The LISA (Laser Interferometer Space Antenna) mission is a space-based gravitational wave detector aiming to detect gravitational waves in a frequency band from 0.1 mHz to 1 Hz. Three satellites arranged in a nearly equilateral triangle with an edge length of about 5 million km will fly in an earth-trailing orbit arround the sun in a distance of 20 ∘. The distance between the satellites will be measured with an interferometer setup. During the mission the distance between the satellites vary with about 50000 km. This breathing of the constellation causes a Doppler shift of the Laser frequency in a range of 2 to 19 MHz.
In this context EADS Astrium developed a RF low noise quadrant photo detector which is suited for high precision phase measurements in a sub-Hz LISA measurement band. It uses an Indium Gallium Arsenide (InGaAs) quadrant photodiode with a total diameter of 1 mm. The detector as a position sensitive device can also be used for the technique of differential wavefront sensing. With respect to the mission requirements the detector has a constant frequency response and a linear phase response for frequencies between 2 and 20 MHz. It has also a path for frequencies between DC and 45 kHz for each quadrant.
In the presentation the setup will be explained and the results of our current measurements will be shown.