Published Papers

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 […]

A combination of the Auto Gain function of the Point Source Microscope (PSM) and the use of an Axicon grating make centering of severely misaligned lenses easy. The lenses in the cell are misaligned far enough that light in the center of the aperture barely makes it through the lens. The PSM video screen displays […]

Recently a customer was using the Point Source Microscope (PSM) to align a slow, singlet objective lens and find its focus.  The customer had a plane retro mirror behind the objective and should have seen a nice round spot at best focus. Instead, he saw a vertical line image as in the following screen shot […]

The Point Source Microscope (PSM) is used to locate the apex of retroreflecting prisms in 3 degrees of translational freedom with a precision of less than 1 micron. The process is easily explained for right angle prisms, as will be done in this paper, but the explanation is valid for cube corner retroreflectors such as those mounted in spherical balls, spherically mounted retroreflectors, or SMRs, for use with laser trackers. With suitable, simple fixtures, the measurements for all 3 directions are made to a precision of < 1 μm in less than 1 minute.

1. INTRODUCTION The premise of this paper is that the only remaining way to improve optical system performance is with better alignment techniques. We feel optical design is a mature field and that little can be done to improve the design of optical systems by improvements to lens design software. The software may become easier […]