Fresnel zone

About: Fresnel zone is a research topic. Over the lifetime, 2337 publications have been published within this topic receiving 37650 citations.

Prism-Enhanced Lenses and Methods of Using Prism-Enhanced Lenses

Abstract: An electro-active lens is presented which utilizes a surface relief structures and an electro-active material, with a change in refractive index facilitating the change in optical properties. A molded structure and a liquid crystal are used to form a diffractive lens. In addition to the classical approach of utilizing diffractive optics and multiple Fresnel zones to form a lens, an additional structure is placed between Fresnel zones in order to improve the diffraction efficiency across the visible spectrum, and reduce chromatic aberration.

Reply to “Comments on `Focusing Characteristics of Curvilinear Half-Open Fresnel Zone Plate Lenses: Plane Wave Illumination'”

Abstract: The present authors reply to the comment by Minin and Minin (IEEE Trans. Antennas Propag., vol.54, no.9, p.2692, September 2006) on the original paper by Hristov et al. (IEEE Trans. Antennas Propag., vol.53, p.1912-19, June 2005)

The optimization of fresnel zone plates for use in focused-beam measurement systems

Abstract: Fresnel zone plates have been used as replacements for doubly-hyperbolic lenses in free-space, focused-beam systems to measure the electrical properties of materials [1]. These zone plates were designed using the traditional method for determining the profile of a zone plate, which is based on optical, ray-tracing principles [2]. In this work, a non-traditional, optimization-based design methodology featuring the genetic algorithm will be explored to determine if the performance of a zone plate can be improved for the focused-beam application. Results will be presented that compare the optimized design to the traditional zone plate and to a doubly-hyperbolic lens.

Mechanical Design of Multiple Fresnel Zone Plates Precision Alignment Apparatus for Twenty-Nanometer Scale Hard X-ray Focusing

Abstract: To overcome the limitations in today's fabrication techniques for high-efficiency Fresnel zone plates (FZPs) capable for hard x-ray focusing in the twenty-nanometer scale, a new approach of stacking FZPs in an intermediate-field was published by Vila-Comamala et al. in 2012 (1). With this approach, a precision alignment apparatus for multiple FZPs handling and aligning must be designed to meet the following challenging design requirements: 1) Each of the stacking FZPs need to be manipulated in three dimensions with nanometer-scale resolution and travel range of several millimeters. 2) The relative three-dimensional stabilities between all of the stacking FZPs (especially in the x-ray beam transverse plane) are required to be kept within few nanometers for more than eight hours, the duration of the hard x-ray focusing for nanoprobe operation. 3) Compatible with the operation of multiple optics configurations for the Advanced Photon Source (APS) future x-ray nanoprobe design. Several prototypes have been designed and tested at the APS. In this paper we present the precision mechanical design of the apparatus prototypes for two, three, and six FZPs alignment in an intermediate-field, as well as the test results of their hard x-ray focusing performances.