Dual recycling is an advanced optical technique to enhance the signal-to-no
ise ratio of laser interferometric gravitational wave detectors in a limite
d bandwidth. To optimise the center of this band with respect to Fourier fr
equencies of expected gravitational wave signals, detuned dual recycling ha
s 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 agreem
ent between the experimental results and numerical simulations has been ach
ieved. (C) 2000 Elsevier Science B.V. All rights reserved.