Abstract

The magnitude of specular and diffuse Fresnel reflectance from powdered samples was investigated with the use of an FT-IR spectrogoniophotometer with wire-grid polarizers mounted in front of and behind the sample. Specular Fresnel reflectance maintains the polarization of the incoming infrared beam and can therefore be eliminated by crossing the orientation of the second polarizer relative to the first. For neat samples, diffuse Fresnel reflectance was found to be only slightly affected by the presence of the two polarizers. While specular Fresnel reflectance is affected by the optical geometry used in making the reflectance measurement, diffuse Fresnel reflectance is unaffected by optical geometry and can only be eliminated by dilution of the neat sample. For dilute samples, the optical geometry and the orientation of the two polarizers slightly affect the absolute intensity of absorption bands, but do not change relative band intensities or band positions.

PDF Article

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription