title: High-efficiency production of propagation-invariant spot arrays.
abstract: Tailoring of the transverse intensity profiles of propagation-invariant optical fields is considered. The design of diffractive elements capable of realizing such fields by Fourier synthesis is discussed. High-efficiency realization of finite-aperture approximations of the constructed fields is demonstrated in a system consisting of two multilevel diffractive elements. The first element is a diffractive toroidal lens, which focuses the incident field into a ring pattern. The second diffractive element, located at the focal plane of the first element, introduces the phase modulation necessary to realize the desired transverse intensity profile behind a separate collimating lens. The influence of the fabrication errors of the diffractive elements on the fidelity of the propagation-invariant spot array is simulated, and system-integration aspects based on substrate-mode planar-integrated optics are considered.
authors.affiliation: Department of Physics, University of Joensuu, Finland. Jari.Lautanen@joensuu.fi
authors.forename: J
authors.initials: J
authors.lastname: Lautanen
authors.forename: V
authors.initials: V
authors.lastname: Kettunen
authors.forename: P
authors.initials: P
authors.lastname: Lakkonen
authors.forename: J
authors.initials: J
authors.lastname: Turunen