A report on the status of the GEO 600 gravitational wave detector

GEO 600 is an interferometric gravitational wave detector with 600 m arms, which will employ a novel, dual-recycled optical scheme allowing its optical response to be tuned over a range of frequencies (from similar to100 Hz to a few kHz). Additional advanced technologies, such as multiple pendulum suspensions with monolithic bottom stages, make the anticipated sensitivity of GEO 600 comparable to initial detectors with kilometre arm lengths. This paper discusses briefly the design of GEO, reports on the status of the detector up to the end of 2002 with particular focus on participation in coincident engineering and science runs with LIGO detectors. The plans leading to a fully optimized detector and participation in future coincident science runs are briefly outlined.