FOURIER-TRANSFORM REFLECTANCE SPECTROMETRY BETWEEN 8000 CM-1 (1.25 MU-M) AND 800 CM-1 (12.5 MU-M) USING AN INTEGRATING SPHERE

Spectral measurements of the directional hemispherical reflectance of samples exhibiting variant reflection behavior were performed in the near and mid infrared spectral region using the integrating sphere method. The main components of the experimental setup were a sphere with a diffuse gold coating and a commercial Fourier transform spectrometer for the spectral analysis of the radiation incident on and reflected by the sample which is located in the center of the sphere. the capability of the device to measure absolute reflectances was tested with polished slices of high purity silicon and germanium, the reflectances of which can be calculated from the refractive indices. Agreement between the measured and calculated values is found to be within 0. 01.