I have an idea for an artificial gravitational lens to be possibly used as a telescope.
First, you would need to make a particle accelerator(PA) in space. A big and very powerful one.
Once you have a PA built in space, charge the ring of the PA with a beam of protons like normal, but continue to accellerate the protons until they become so massive as to create a gravitational lens on the inside of the ring. The resolution of the telescope would only likely be limited by the strength of the PA.
One would then be able to see with FAR FAR greater clarity than a traditional telescope, because you wouldn't be limited by the shape, size, or smoothness of the mirror. Space is infinitely smooth.
Gravitational Lensing of course is already possible if we had a close enough black hole so that we wouldn't have to build a PA to create an artificial lens. Of course, nobody wants to live nextdoor to a black hole, so this idea sidesteps all of that, aside from the fact that we do not live next to a black hole!
I have to wonder now -- If a smaller version of this could be made, and formed into a microscope here on earth.
Imagine a small PA ring used as the lens in a microscope. Using gravity as the lens, you could see FAR FAR clearer images and you wouldn't have to damage the material in order to view it under the microscope.
This could revolutionize the microscope industry!!!