Plans for a large gravitational wave antenna in Germany

A gravitational wave antenna design is outlined. Arms 3 km in length are proposed, as a tradeoff between cost and the influence of thermal mirror motion. Tunnels, completely or partly below the surface, are to house the vacuum tubes. Besides the standard single 90 deg interferometer, a redundant triangular configuration consisting of three 60 deg interferometers is considered. The size of the mirrors depends on the choice between delay lines and Fabry-Perot cavities. A set of relatively large mirrors is to be manufactured and tested. Components for light modulation and guiding need research. Light power enhancing techniques (injection locking, recycling) are to be investigated. Improved frequency stabilization is to be developed, and phase modulation of the laser light (to reduce noise due to scattered light) is to be tried.