Apochromat

About: Apochromat is a research topic. Over the lifetime, 642 publications have been published within this topic receiving 7934 citations.

Color hologram reconstruction based on single DMD

Abstract: Because of the magnification chromatic aberration and the transverse chromatic aberration caused from different wavelengths of color lasers in the process of color holographic optoelectronic reconstruction based on DMD, the reconstructed holograms of three color components can not coincide. Firstly, on the reference of blue color component, the magnification chromatic aberration of the original image is eliminated. Secondly, according to the analysis of the incident angles of three lasers, the transverse chromatic aberration is eliminated by adjusting the incident angles. At last, the synthesized color hologram is obtained by means of the experiments based on DMD. The method proposed in this paper does not use any lens, so there is no axial chromatic aberration.

Optical element for correction of chromatic aberration, optical pick-up device having optical element for correction of chromatic aberration, optical reproducing device having optical pick-up device and optical recording and reproducing device

Abstract: This invention provides an optical element for correcting a chromatic aberration corresponding to a short wavelength of a light source and further provides an optical pick-up device having the optical element for correcting a chromatic aberration and adapting for a further higher recording density and larger capacity of the optical recording medium, the optical reproducing device and the optical recording and reproducing device. The optical element for correcting a chromatic aberration arranged between a light source such as a semiconductor laser or the like with a wavelength being 440 nm or less and an objective with numerical aperture NA being 0.55 or more, a focal distance being 1.8 mm or more and an Abbe number at the d-line (587.6 nm) being 95.0 or less has a convex lens with at least an Abbe number at the d-line being 55 or more and a concave lens with an Abbe number at the d-line being 35 or less.

Modelling the primary chromatic aberrations and secondary spectrum of conceptual thick-lens modules

Abstract: A virtual thick-lens module comprising three air-spaced thin lenses is proposed, which is able to have the identical primary chromatic aberrations and secondary spectrum for just real thick lenses, or groups or components within any thick lens, hence it is capable of studying the chromatic aberration behaviours of conceptual lenses without their detailed structures. The three thin-lens powers are first evaluated to match the required first-order quantities. Then the chromatic aberration coefficients of each thin lens are solved to satisfy the given system aberrations associated with the reference optical configuration. When the incident rays are changed, each thin lens will induce new chromatic aberrations according to the thin-lens formulae. The new system aberrations are obtained by adding those individual thin-lens aberrations together. The module can be directly applied to finite and infinite conjugates, focal and afocal lenses, as well as telecentric and non-telecentric lenses. Evaluations of the chr...

Image Processing Based on Moving Lens with Chromatic Aberration and Monochromatic Image Sensor

Abstract: Embodiments of imaging devices of the present disclosure obtain color images from a monochromatic image sensor based on a series of several images taken at different focal positions of an optical imaging lens possessing a chromatic aberration.

A Low-cost Optimization Design for Minimizing Chromatic Aberration by Doublet Prisms

Abstract: A low-cost optimal double-prism method is proposed by using the developed MATLAB program to correct chromatic aberration. We present an efficient approach to choose a couple of low-cost glasses to obtain a low aberration double prism. The doublet prisms were made of two lead-free glasses. The relative partial dispersion of the two lead-free glasses is identical and their Abbe numbers are different greatly. The proposed design aims to minimize chromatic aberration, such as in apochromats, for paraxial ray tracing. Finally, an optimization design for real ray tracing can be evaluated by the chromatic aberration curve with a minimal area.