Development of a compact tool for sealing the compensator group in final stages of alignment

Abstract

A high-precision, low-cost tool for optimal alignment of a compensator group in anamorphic objectives is presented. The system provides highly accurate information by analyzing the axis and field PSFs in the focal plane of the optical system under test. The PSFs are provided by a bundle of 9 different pigtailed laser diodes placed in the object field, and they are recorded by a lensless 2/3" CCD camera. The comparison of the simulated and obtained PSFs allows determining the optical element introducing the differences so action may be taken precisely on that element. The system is especially useful in non-rotationally symmetrical systems, where errors in axis position result into asymmetries of the PSF images. The tool is used for precise alignment of the cylindrical lenses in the compensator group of an anamorphic objective prior to sealing. Results show the system is able to detect misalignments of 100µm and axis positioning errors of just 30arcsec using off-the-shelf components without the need of high-precision positioning equipment.

Peer Reviewed

Postprint (author's final draft)