Thought experiment. Imagine building two optical mirrors around the sun an astrophysical body of the right mass, lined and diametrically opposed, at the right distance so that the sun is acting as a gravitational lens. Mirror A reflects the light from any extrasolar object and directs it to mirror B. Because of lensing, the image arrives amplified. Mirror B reflects the light back to A, so the image is again amplified. And so on. Would it work?