Hi,
I was thinking about the relationship between the polarization of spacetime via electromagnetic waves, and the ripples in spacetime via gravitational waves, and how to connect the two. Ripples in space time should cause the electromagnetic wave orthogonal polarization in spacetime to either aim inwards or outwards depending on the gravitational wave ripple surface normal angle. Also perhaps sufficient polarization of spacetime could cause a gravitational ripple in spacetime itself?
If there is a gravitational ripple in spacetime, with a coherent superimposed EM field polarization, if the wavelength of the gravitational ripple matches the wavelength of the EM field polarization, the E field peaks could turn inwards and exert a repulsive electric field force that would counteract the gravitational wave ripple amplitude. Same applying for the magnetic field and also attractive or repulsive depending on the configuration.
So to test that idea of being able to module gravitational fields as well as electromagnetic fields, I would suggest the idea of a spacetime laser.
The standard laser uses coherent waves, but the spacetime laser could maybe use precisely stacked coherent EM waves.
The reason for the precisely stacked coherent waves, is so that the E field and B field can interfere with the next neighbor waves.
For example, the polarization field of one coherent wave will be repelled by the next neighbor coherent wave. This continues over the whole stack of coherent waves, giving the whole stack an overall bias curvature. This curvature would be a curvature in the gravitational field, and the laser will emit light in that curved path.
If none of that works, it may require an existing gravitational wave which could then be amplified or attenuated by the stacked coherent EM waves too, also it could work to detect gravitational waves in that case.
cheers, Jamie