Not to sound condescending, but… You can transmit data by modulating in on top of something that propagates through space? Well, big deal, who'd thought? /s In all seriousness, the big problem is, how to create gravitational waves in a controlled manner in the first place. Because the fact remains, that gravity is, by several orders of magnitude, the weakest force in our universe and it takes stooopid amounts of ener…
And "end facets of the optical filter"? What is being thrown around?