Building a Gravitational Wave Observatory: The story of GEO600

by Martin Hewitson (Albert-Einstein-Institut,Hannover)

GEO600 is a dual-recycled Michelson interferometer with 600m arms located south of Hannover, Germany. For the past 10 years GEO600 has gone through various stages of construction and commissioning, as well as multiple observation runs of varying lengths which has led the instrument to have a peak sensitivity around 500Hz of 2e-22 in strain, or about 2e-22m. Throughout all this time, GEO600 has been at the forefront of technology development for ground-based Gravitational Wave detectors, as well as pioneering various analysis and commissioning techniques. This talk will describe: the construction and layout of GEO600; some of the technologies that make GEO600 unique; the many noise sources present in such a complex, sensitive instrument; some of the characterization methods and results, as well as details of the calibration of the instrument. We will then go on to discuss the future of GEO600 as it continues to implement advanced technologies, paving the way for the 2nd and 3rd generation large- scale detectors planned for the next decade.