Published Papers

Axicon gratings are computer generated holograms of equally spaced concentric circles printed on a plane substrate. When illuminated by a point source of light they create axes in space defined by a line between the point source and the center of the grating pattern. The axis can be viewed in either transmission or reflection with an autostigmatic microscope. The axis created by the grating can be located to less than 1 um in translation and depending on distance from the grating to less than 1 microradian in angle. Several examples of such a use in alignment are explained.

The positioning accuracy of multi-axis machine tools and coordinate measuring machines are often checked using ball bars or ball plates where the spatial locations of the balls are externally calibrated to provide a traceable artifact [1,2]. In use, the individual ball surfaces are probed in at least 4 places with a tactile sensor and the points of contact fit to the equation of a sphere to determine the center of the ball. The method is tedious, indirect and semi-static. Furthermore, it is difficult or impossible to create artifacts that truly span the three-dimensional work volume of machines because some features become occluded by others and cannot be accessed.

This brief chapter serves as a vital addendum to the last two chapters. While I’ve already described the alignment process, I realized I hadn’t emphasized how remarkably simple it is—and what makes it so effortless. Over the years, countless methods have been used to align optics successfully, long before Bessel beams entered the picture. What […]

In Chapter 14, we showed how to determine the axis of a laser beam to which we want to align optical elements and then how to align a Bessel beam to the laser beam axis. This Chapter shows the steps to align optical elements to the reference Bessel beam. With tabletop alignment, you have all […]

At last, I am back to writing more about optical alignment. The hiatus was due to my realization that most readers are not interested in assembling lenses in a tube. Rather, they want to align free-standing optics on tabletops or benches in labs researching topics like laser light interactions with matter, free-space communication, and quantum […]

In Chapter 12, I commented again on classical optical instruments since there was interest in an earlier discussion. This got me thinking about what had changed in optical technology since the period ending about 1950 when there was a rather canonical set of classical optical metrology tools. There has been a huge technological change since […]