Abstract

The spaceborne gravitational wave detector LISA (Laser Interferometer Space Antenna) utilizes free floating proof masses as inertial references for its 5 million km long interferometer arms. In the current baseline design their position and tilt with respect to the appropriate optical bench is measured by an optical readout which needs picometer sensitivity in translation measurement and nanoradian sensitivity in tilt measurement. For this purpose EADS-Astrium GmbH - in cooperation with HTWG Konstanz and the Humboldt-Universität zu Berlin – developed a highly symmetric heterodyne interferometer [1] with differential wavefront sensing for the tilt measurement [2].

© 2009 IEEE