Published Papers

Methods of centering without using a precision rotary table to establish a reference axis in space are several times faster than with a rotary table. However, finding an optimum method of establishing an alternative reference axis is challenging. We look at the small class of centering situations involving the precision cementing of doublets to illustrate the advantages of using a Bessel beam as the reference axis. Two approaches to centering illustrate the method: one involving first aligning the meniscus element and then adding the positive element, and the other, cementing the two elements and aligning the pair.

ABSTRACT 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 […]

EXPERIMENTAL SETUP: A Point Source Microscope (PSM) was mounted on a motorized vertical stage above a 25 mm diameter, 200 mm efl lens sitting above a plane mirror. A square black paper mask with an 8 mm diameter hole was placed over the lens as shown in the figure below to give an f/25 aperture. […]

Customers purchasing a PSM often ask me if we offer mounting hardware for the PSM like x-y-z stages. MY ANSWER HAS BEEN “NO”, BECAUSE THERE ARE SO MANY WAYS OF USING THE PSM THAT IT WOULD BE IMPOSSIBLE TO MEET EVERYONE’S DIFFERENT NEEDS. IN FACT, THE ANSWER IS “YES!” The centering station is a tall, […]

Can the PSM find best focus of an f/25 optical system to less than ± 10 μm? SOMEWHAT SURPRISINGLY, YES, TO ABOUT ± 2 ΜM. You scan axially through best focus several times and plot the number of pixels above threshold versus scan distance. The curve is quadratic and the derivative of the curve fit […]

The MicroFinish Topographer helped bring you this spectacular image of the sun. The smoothness criterion on the Daniel K. Inouye Solar Telescope primary mirror was a scatter specification. This was a problem in two respects, the mirror substrate was Zerodur and the scatter angle was too close to specular to measure with a scatterometer. The […]