Speaker
Description
That light propagating in a gravitational field gets
frequency-shifted is one of the basic consequences of any metric theory
of gravity rooted in the equivalence principle. At the same time, also a
time dependent material's refractive index can frequency-shift light
propagating in it. The mathematical analogy between the two effects is
such that the latter has been used to study the optical analogue of a
black-hole spacetime. Here, we combine these two effects by showing that
light propagation in non-linear media in the presence of a moving
refractive index perturbation can lead to a gravity-dependent blueshift.
We find that the predicted blueshift surpasses the gravitational
redshift even if the medium is considered to be perfectly stiff. In
realistic scenarios, by far the strongest frequency shift arises due to
the deformation of the dielectric medium and the corresponding
photoelastic change of refractive index. This has the potential to
facilitate optical sensing of small gravity gradients.
