Use Of Aspheres Research Articles

Optical design and implementation of a compact and long focal length imaging system

In this paper, we demonstrate a compact and long focal length imaging system for building detection. This system is an all-spherical system. In order to avoid the use of aspheres, the system relies on two groups of correction elements to correct aberrations. This allows for short manufacturing cycles and simplified adjustments. The system works in the visible band from 460 nm to 750 nm. The focal length is 900 mm, and the optical length is only 280 mm. The designed modulation transfer function (MTF) is consistent with the diffraction limit. The MTF curve is 0.63 at the Nyquist frequency of 78 lp/mm. The optomechanical structure is developed based on the analysis consequence of tolerance and stray light, and a device is fabricated. We also propose a simplified method for measuring the space between the primary mirror and the secondary mirror in a compact coaxial optical system. According to the experimentation, the device is proven to meet the application requirement. Detailed descriptions of the design and implementation are provided.

Aspherics in spectacle lenses

Abstract A review of the use of aspherics in the last decades, understood in a broad sense as encompassing single-vision lenses with conicoid surfaces and free-form and progressive addition lenses (PALs) as well, is provided. The appearance of conicoid surfaces to correct aphakia and later to provide thinner and more aesthetically appealing plus lenses and the introduction of PALs and free-form surfaces have shaped the advances in spectacle lenses in the last three decades. This document basically considers the main target optical aberrations, the idiosyncrasy of single lenses for correction of refractive errors and the restrictions and particularities of PAL design and their links to science vision and perception.

Design of Double Gauss Systems Using Aspherics

A study of the use of aspherics in the design of double Gauss lenses optimized at f/2 with a total field of view of 42 degrees has been performed. Several specific designs incorporating one or two aspheric surfaces at different positions in the lens are presented. The aspheric designs yield substantially increased resolution as compared with an optimized spherical system.