Published Papers

Bessel beams have found use in the alignment of transmissive optics for some time. They are also used for the alignment of reflecting optics when used in the imaging mode, that is, when the wavefront is near spherical. However, there are cases where it would be useful to use the Bessel beam for alignment of far-off axis aspheres to order to get the asphere aligned close enough to its final position that light will go through the system in the imaging mode. In another mode, the Bessel beam is used to determine the normal to a free form surface.

The use of artificial intelligence (AI) software for wavefront sensing has been demonstrated in previous studies [1], [3]. In this work, we have developed a novel approach to wavefront sensing by coupling an AI software with an Autostigmatic Microscope (AM). The resulting system offers optical component and system testing capabilities similar to those of an interferometer used in double pass, but with several advantages. The AM is smaller, lighter, and less expensive than commercially available interferometers, while the AI software is capable of reading out Zernike coefficients, providing real-time feedback for alignment.

Although this is a chapter on off-axis parabolas (OAPs), I want to start with one more way of testing symmetric parabolas because it illustrates a point about off-axis alignment. Assume we have a symmetric parabola with no central hole and we want to minimize the obstruction due to testing. If we set the parabola up […]

I often receive requests for assistance with aligning parabolic mirrors, particularly off-axis ones. Interestingly, with the right tools, the actual alignment process is often quicker than mounting the optical alignment equipment. This observation led me to reflect on the tools themselves. Currently, no traditional method—whether using an autocollimator or an alignment telescope—provides an effective way […]

The Point Source Microscope (PSM) is used to find five aberrations related to the symmetries of the autostigmatic image viewed when aligning aspheric mirrors to a point along an axis. These five aberrations exactly match in number the five degrees of mechanical freedom required to align the mirror to an axis and thus provide an exact solution to a unique focus and alignment to an axis. We show how the PSM is used to capture and analyze a set of images as the PSM is moved through focus using the symmetry properties of the image.

We present a description of an attachment for an autostigmatic microscope that uses two objectives set at right angles to unambiguously locate the center of a ball in all 3 translational degrees of freedom that can be used to perform the “R” test, or to scan a ball plate, to determine machine tool precision dynamically.