We have extended the method of Alvarez [J. Am. Optom. Assoc. 49, 24 (1978)] to generate a variable magnitude of third-order spherical and/or coma aberration by using a combination of fourth-order plates with a magnification system. The technique, based on the crossed-cylinder aberroscope, is used to measure the wave-front aberration generated by the plates. The method has been applied to correct the third-order spherical aberration generated by an artificial eye as well as the coma produced by a progressive addition ophthalmic lens. The simplicity of the method and its relatively low cost make it attractive for partial correction of the aberrations of the eye.

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Generation of third-order spherical and coma aberrations by use of radially symmetrical fourth-order lenses

An aberration corrected electron microscope is used to create electron diffraction catastrophes, containing arrays of intensity zeros threading vortex cores. Vortices are ascribed to these arrays using catastrophe theory, scalar diffraction integrals, and experimentally retrieved phase maps. From measured wave function phases, obtained using focal-series phase retrieval, the orbital angular momentum density is mapped for highly astigmatic electron probes. We observe vortex rings and topological reconnections of nodal lines by tracking the vortex cores using the retrieved phases.

Electron Vortex Production and Control Using Aberration Induced Diffraction Catastrophes

Advanced techniques for measuring primary mirrors for astronomical telescopes.

The tolerances on optical systems and components are usually very tight and the testing of such products is a vital part of their manufacture. This review describes how the interference properties of light have been applied to optical testing and indicates the main fields of application of the various techniques.

Interferometric testing of optical systems and components: a review

Optical testing: a review and tutorial for optical engineers

In order to obtain a rapid estimate of the quality of a lens by observing its behaviour in the interferometer, it is necessary for the observer to be familiar with the characteristic patterns of the various primary aberrations under various conditions of adjustment. A method is described by which these patterns can be easily calculated for any required case; and series of typical patterns are shown together with actual interferograms for comparison.

The interferometer patterns due to the primary aberrations

https://iopscience.iop.org/article/10.1088/1475-4878/27/2/304/pdf

R. Kingslake

Papers

The interferometer patterns due to the primary aberrations

The interferometer patterns due to the primary aberrations