Apochromat

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

Variation of the Axial Aberrations of Electron Lenses with Lens Strength

Abstract: The variation of refractive power and spherical aberration with electrode voltages and field strengths is studied for two characteristic unipotential lenses, an immersion lens, and a magnetic lens. Conclusions are drawn herefrom regarding the variation, with lens strength and applied voltage, of the resolving power obtainable with the lens as an electron‐microscope objective. Scattered measurements by other authors agree satisfactorily with the results. The ``relativistic aberration'' of the electrostatic unipotential lenses, i.e., the effect on the image of fluctuations in the over‐all applied voltage, is calculated and shown to be of significance in the electrostatic electron microscope. Furthermore, the axial chromatic aberrations are computed for the four systems and the question of upper limits of the last two aberrations is discussed.

Glass selection for airspaced apochromats using the Buchdahl dispersion equation

Abstract: The Buchdahl dispersion equation is applied to a system of airspaced thin lenses. The powers, airspaces, and glass dispersion characteristics of a lens system are represented as a series of vectors. The sum of these vectors represents the state of paraxial color correction of the lens system. The vector representation is used as a guide in the selection of glasses for airspaced doublets (dialytes), triplets, and more complex lens systems with apochromatic color correction. Prescriptions and performance data are given.

Apochromatic singlets enabled by metasurface-augmented GRIN lenses

Abstract: Chromatic aberrations are a primary limiting factor in thin, high-quality imaging systems. Recent advances in nanoscale manufacturing, however, have enabled the creation of metasurfaces: ultra-thin optical components with sub-wavelength features that can locally manipulate the wavefront phase. Meanwhile, there has been renewed interest in GRadient-INdex (GRIN) lenses due to the extended degrees of design freedom they offer. When combined, these two technologies can provide unparalleled imaging system performance while realizing drastic reductions in size, weight, and power. Through paraxial theory and full ray tracing we produce a lens singlet that can achieve three-color (apochromatic) correction by employing a metasurface-augmented GRIN. This apochromatic singlet has the potential for application in high-quality optical systems.

Achromatic ophthalmic lenses

Abstract: A compound ophthalmic lens (10) having improved chromatic aberration is provided which includes a polymerized resin superstrate lens (20) formed on a substrate lens (30). The chromatic dispersion characteristics of the resin (20), as well as its refractive index, are matched to the substrate lens (30) to obtain the desired Abbe number, lens power and thickness of the finished lens (10), and to render the interface between the substrate lens (30) and the superstrate lens (20) substantially invisible. The color dispersion of the substrate lens (30) is compensated for by the superstrate lens (20) which has a relatively low Abbe number and has an opposite power from the substrate lens (30).

Zoom lens design using liquid lenses for achromatic and spherical aberration corrected target

Abstract: This paper proposes a zoom lens system based on liquid lenses. The system design consists of a fixed lens and four two-chamber liquid lenses. The chambers are filled with different liquids. The design principle is analyzed. Optimization method is used to get the optimal solution. With the solution, the proposed zoom lens system can obtain achromatic and spherical aberration corrected images in a particular zooming range, and no moving element is needed in the proposed zoom lens system. By choosing proper liquids, it can be designed to work within particular working regions with improved optical performance. We give the detailed simulation examples. The results indicate that the proposed design can help to improve the optical performances of zoom lens systems.