See the end of the article, after further research quantum gravity could be simulated on a quantum computer. The links between research on quantum computing and quantum gravity are fascinating anyway!
Where is the source? Tantalo does not produce photons, it is not like GaAs that you can pump and get stimulated emission. The Nature paper does not have laser in the title.
Title is misleading. This is about integrated optics that can do "computation" on the frequency of laser input using all kinds of nonlinear optical effects.