Effect of Light Polarization in ATR Geometry

The various spectra have been recorded under a square-wave modulation of the potential between the two values indicated below the curves. They represent the change in absorbance when the potential is changed from the lower to the higher value. The change in shape is consistent with a broad distribution of interface states through the gap. It is associated with the increasing energy of the surface Fermi level (increased 

As shown in Section 6.2, when using an internal-reflection geometry, the direction of the electric field of the IR beam at a planar interface crucially depends on beam polarization. As a result, IR absorption depends on the polarization of the beam. Polarization in the IR range is conveniently fixed by grid polarizers, which are commercially available at moderate prices and can be easily inserted into the beam. 

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