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Performance of a 1200m long suspended Fabry-Perot cavity

A. Freise·M. M. Casey·S. Gossler·H. Grote·G. Heinzel·H. Lueck·D. I. Robertson·K. A. Strain·H. Ward·B. Willke·J. Hough·K. Danzmann
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Abstract

Using one arm of the Michelson interferometer and the power recycling mirror of the interferometric gravitational wave detector GEO600, we created a Fabry-Perot cavity with a length of 1200 m. The main purpose of this experiment was to gather first experience with the main optics, its suspensions and the corresponding control systems. The residual displacement of a main mirror is about 150 nm rms. By stabilising the length of the 1200 m long cavity to the pre-stabilised laser beam we achieved an error point frequency noise of 0.1 mHz/sqrt(Hz) at 100 Hz Fourier frequency. In addition we demonstrated the reliable performance of all included subsystems by several 10-hour-periods of continuous stable operation. Thus the full frequency stabilisation scheme for GEO600 was successfully tested.

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A. Freise, M. M. Casey, S. Gossler, H. Grote, G. Heinzel, H. Lueck, D. I. Robertson, K. A. Strain, H. Ward, B. Willke, J. Hough, K. Danzmann. 2001-11-05. Performance of a 1200m long suspended Fabry-Perot cavity. https://doi.org/10.1088/0264-9381%2F19%2F7%2F322

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