Answers are grounded in this paper and cite their sources.
We introduce a family of spherically symmetric gradient-index lenses forming a perfect (sharp) image of any point of the space in three dimensions, including the points of a homogeneous (constant refractive index) region. The only previously known example of an optical instrument with such properties is the plane mirror (or combinations thereof).
No takes yet. Share an insight, caveat, or question.
Juan C. Miñano (2006) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: