Optical accessory for variable angle reflection spectroscopy

摘要

A variable angle reflection accessory for use in reflection spectrometry characterized by a pair of fixed ellipsoidal reflectors positioned inside an enclosure adjacent a sample surface on the outside of the enclosure and a pair of rotatable plane mirrors positioned at opposite sides of the sample surface. The spectrometer beam is brought to a focus at the first plane mirror, from which it is reflected off the first ellipsoidal reflector to a focus at the sample surface. The reflected beam follows a corresponding path back to the spectrometer. Rotating the mirrors in unison causes the beam angle of incidence on the sample surface to vary over a wide range while maintaining optical alignments and continuing to center the radiation on the same sample area. The outside positioning of the sample surface allows the accessory to be easily coupled to a purge port of the spectrometer and allows rapid sample exchanges without breaking the purge atmosphere.