title: Perfect imaging in a homogeneous threedimensional region.
abstract: 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).
authors.forename: Juan C
authors.initials: JC
authors.lastname: Miñano