Gravitational Lensing of Gravitational Waves from Inspiraling Binaries by a Point Mass Lens

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 ~10²M_, 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.