title: Electromagnetic design of an all-diffractive millimeter-wave imaging system.
abstract: We present the design and electromagnetic analysis of an all-diffractive millimeter-wave imaging system having a field of view of +/- 15 degrees. This system consists of two 16-level diffractive lenses, with the stop in contact with the first lens. By considering the Seidel aberrations for a diffractive lens and applying the corresponding stop shift formula, we established the expressions of third-order wave aberrations for this system. By setting all primary Seidel aberrations to zero and solving the corresponding system of equations, we obtained two sets of solutions for this two-element all-diffractive system, which totally compensate for all Seidel aberrations. To assess image system performance, we apply the finite-difference time-domain technique and a vector plane-wave spectrum method, in combination, to validate the performance of the system. To reduce the computational cost and thereby enable the complete electromagnetic analysis of the system, a four-step analysis procedure has been developed and applied as an electromagnetic system model.
authors.affiliation: Department of Electrical and Computer Engineering, University of Delaware, 140 Evans Hall, Newark, Delaware 19716, USA. caihua@udel.edu
authors.forename: Caihua
authors.initials: C
authors.lastname: Chen
authors.forename: Shouyan
authors.initials: S
authors.lastname: Shi
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Prather