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 nonchromatic 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.