INTERFEROMETRIC ANTENNA RESPONSE FOR GRAVITATIONAL-WAVE DETECTION

The interferometric antenna response to gravitational-wave excitation is studied with the Fermi Normal Coordinate (FNC) reference system, wi th the limit that the gravitational wavelength must be much larger tha n the interferometric arm length, An optical configuration of the ante nna, quite similar to the one generally considered in the long-baselin e antenna projects, has been studied, i.e., Fabry-Perot optical caviti es in the interferometer arms and reflectors at the input and the outp ut of the interferometer for the purpose of recycling both the laser p ower and the output signals. An exact computation of the antenna respo nse is given in a form that is also suitable to provide directly the r esponses for simplier optical configurations without the power or the signal recycling. Furthermore the response of the antenna for the narr ow-band detection mode is also calculated. The results obtained in the FNC gauge at rest with the antenna are consistent with the ones given in the literature that were computed in the transverse traceless gaug e at rest with the gravitational radiation.