Unstable optical resonator with self-imaging aperture

摘要

An unstable optical resonator with self-imaging aperture having at least two reflecting surfaces and a primary outcoupling aperture in optical alignment with each other. In the resonator the result of a single round-trip propagation is to image the primary aperture at its own plane. The self-imaging condition is met when a pass through the resonator, starting at the outcoupling aperture, produces an infinite Fresnel number.