2019ApJ...875..139L

Gravitational wave predicted by general relativity is the transverse wave of spatial strain. Several gravitational waveform signals from binary black holes and from a binary neutron star system accompanied by electromagnetic counterparts have been recorded by the advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and the advanced Virgo. In analogy to light, the spatial fringes of diffraction and interference should also exist as the important features of gravitational waves (GWs). We propose that observational detection of such fringes could be achieved through gravitational lensing of continuous GWs. The lenses would play the role of the diffraction barriers. Considering peculiar motions of the observer, the lens, and the source, the spatial amplitude variation of diffraction or interference fringes should be detectable as an amplitude modulation of a monochromatic gravitational signal.