Experimental Alignment of a Spectrometer System Using Laser Diffraction

Abstract

A simple technique is described to facilitate precise three-dimensional alignment of a monochromator relative to a dimensionally fixed optical feed system. This technique uses diffraction of a He-Ne laser through the entrance slit of the monochromator. Diffraction pattern symmetry serves as a sensitive visual guide. Reduction of a three-dimensional alignment problem into a simpler two-dimensional one is achieved by the utilization of a “rail and rider” approach accompanied by systematic placement and mechanical alignment of components. Considerable time savings using this approach have been realized.