title: Basic categories of dual-contour reflective-refractive aplanats.
abstract: We derive, illustrate, and analyze previously unrecognized basic categories of dual-contour reflective-refractive aplanats, evaluated for solar concentration.
authors.forename: Heylal
authors.initials: H
authors.lastname: Mashaal
authors.forename: Daniel
authors.initials: D
authors.lastname: Feuermann
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Gordon