TITLE: Is it possible to make an optical lense that is an analog to a gravitational lense?
QUESTION [3 upvotes]: There are many lenses that do all sorts of things. eg. horshoe lenses twist light, meta material lenses can boggle the mind.
Is it possible to make an optical lense that is an analog to a gravitational lense?

REPLY [8 votes]: Yes, it's not only possible but relatively easy. For a gravitational lens the deflection angle at a distance $r$ from the black hole is approximately proportional to $1/r$. So your lens is going to look something like a hyperboloid of revolution:

Note that the light rays are bent increasingly strongly as you approach the axis.
This type of lens has been made and a Google will find you many examples. See for example this gravitational lens simulator.
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