Gravitational lensing of gravitational waves from inspiraling binaries is discussed in the context of advanced laser-interferometer detectors, taking correct account of the diffraction effect. Convolving the spectrum of the lensed waveform with that of the detector noise, we calculate how much the signal-to-noise ratio is magnified by gravitational lensing as a function of the mass and position of the lens. When the lens is much lighter than $\sim {10}^2{M}_{\odot }$, the diffraction is so effective that the wave flux is not magnified appreciably. We predict that lensed waveforms are distinguishable from unlensed ones in that the signal-to-noise ratio shows an oscillatory behavior as the frequency sweeps up.

• Received 10 September 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.1138