Signal recycling and resonant sideband extraction
Signal recycling
Signal recycling improves the sensitivity of an interferometer by adding a partially reflective mirror at the output port. This improves of the fringe-contrast of the whole interferometer and allows shaping the frequency response of the instrument – tuning it for certain gravitational-wave signals.
GEO600 researched different signal-recycling configurations in detail, which resulted in a considerable sensitivity improvement at high frequencies.
Resonant Sideband Extraction
An interferometer with resonant sideband extraction can be manipulated in such a way that its optical response to effects from gravitational waves can be optimized frequency dependent – independently of other parameters of the interferometer.
Relevant publications
1.
Heinzel, G.; Freise, A.; Grote, H.; Strain, K. A.; Danzmann, K.: Dual recycling for GEO 600. Classical and Quantum Gravity 19 (7), pp. 1547 - 1553 (2002)
2.
Heinzel, G.; Mizuno, J.; Schilling, R.; Winkler, W.; Rüdiger, A.; Danzmann, K.: An experimental demonstration of resonant sideband extraction for laser-interferometric gravitational wave detectors. Physics Letters A 217 (6), pp. 305 - 314 (1996)
3.
Mizuno, J.; Strain, K. A.; Nelson, P. G.; Chen, J. M.; Schilling, R.; Rüdiger, A.; Winkler, W.; Danzmann, K.: Resonant sideband extraction: a new configuration for interferometric gravitational wave detectors. Physics Letters A 175 (5), pp. 273 - 276 (1993)
4.
B. J. Meers
Recycling in laser-interferometric gravitational-wave detectors
Phys. Rev. D 38, 2317 (1988)