Papers Published by Optical Perspectives Group

Bessel beams are useful for alignment because they create a small diameter, bright, straight line image in space perpendicular to the Axicon, or Axicon grating, producing the beam that is an exact analog of a single ray in a ray tracing program. Here we limit our discussion to Bessel beams produced by plane gratings whose pattern is evenly spaced concentric circles that are illuminated by a point source of light on the grating axis. The gratings produce a more nearly ideal Bessel beam than a lens type Axicon, and the plane grating serves as a plane mirror as well in an alignment setup, so the combination defines four degrees of freedom in space rather than the usual two.

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 […]

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 […]

1. INTRODUCTION Finding the optical axis of an aspheric surface is an essential part of making an aspheric lens because the center of curvature, or optical axis, of the second side must lie on, or be coincident with, respectively, the optical axis of the first side for maximum optical performance. Looking at the center of […]