REFLECTANCE SPECTROPHOTOMETRIC APPARATUS WITH TOROIDAL MIRRORS

摘要

An apparatus uses reflectance spectrophotometry to characterize a sample (16) having any number of thin films. The apparatus uses two toroidal mirrors (33, 34) in an optical relay to direct light reflected by the sample (16) to a spectrophotometer (26). A computer then analyzes the reflected spectrum to characterize the optical properties of the sample (16). The optical relay allows a range of angles of reflection from the sample (16), and has no chromatic aberration. The optical relay is also arranged so that the non-chromatic aberration is minimized. The sample (16) is mounted on a movable stage (14) so that different areas of the sample (16) may be characterized. Furthermore, a deflector (24) and a viewer (28) are used to allow the operator of the apparatus to view the region of the sample (16) under study.