New Physical Optics Method for Curvilinear Refractive Surfaces and its Verification in the Design and Testing of W-band Dual-Aspheric Lenses
Abstract
We proposed new design concepts and solutions for non-paraxial quasi-optical dielectric lenses that exceed in performance more conventional approaches. One of new advances is the use of optimized dual-aspheric surfaces for dielectric lenses which allow one to minimize (and equalize) the refraction angles at the lens opposite surfaces. This reduces the total on-axis thickness of the lens which is important under the conditions of significant non-paraxial operation of the lens. In addition, this also reduces the aberrations of polarization pattern in the image domain. Another advance is the use of split-step double-sided Fresnel profile of the lens along with optimized dual-aspheric shape of lens surfaces between the Fresnel steps. This design solution should further reduce both the lens thickness and possible aberrations as compared to more conventional solutions. For the electromagnetic analysis and simulation of dielectric lenses of complicated shape and design, we have proposed a new kind of asymptotic hybrid approach that combines both the wave-based and ray-tracing approximations in an improved manner which is based on the use of newly proposed extended physical optics (EPO) diffraction integral formulation specifically created for the modeling of quasi-optical components with curvilinear refractive surfaces. We also made focal field measurements of double-sided split-step dual-aspheric mm-wave Fresnel lenses designed for producing well-shaped Gaussian beams in the focal domain. Two lenses, one of Teflon and another of polyamide, were compared in their performance with a double-sided Fresnel lens of different design, with full height of Fresnel steps. We confirm a good focusing ability of all the lenses. They produced the target beam width according to the design. Yet, the lenses of split-step design are thinner, have lower insertion losses, and a greater focal depth as compared to more conventional Fresnel lenses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2013
- Accession Number
- ADA594248
Entities
People
- Ayhan Altintasa
- Vladimir B. Yurchenko
Organizations
- Bilkent University