Demonstration of detuned dual recycling at the Garching 30 m laser interferometer

Dual recycling is an advanced optical technique to enhance the signal-to-noise ratio of laser interferometric gravitational wave detectors in a limited bandwidth. To optimise the center of this band with respect to Fourier frequencies of expected gravitational wave signals, detuned dual recycling has to be implemented. We have demonstrated detuned dual recycling on a fully suspended 30 m prototype interferometer. A control scheme that allows the detector to be tuned to different frequencies will be outlined. Good agreement between the experimental results and numerical simulations has been achieved. (C) 2000 Elsevier Science B.V. All rights reserved.