On the determination of optical constants in the infrared by attenuated total reflection

Surface Infrared Spectroscopy

“…In addition, the depth of penetration term in the second viewpoint is a function of IE,I2 rather than the amplitude of E,. (5,6,24,25,27,36,37,39,40,42,57) Similar to the depth of penetration term in the first viewpoint of the sampling depth, two definitions of the depth of penetration term have also been used in the second viewpoint of the sampling depth. In addition, the difference between the two definitions involves the predesignated decay of the intensity of the radiant energy associated with the electromagnetic field.…”

“…(3,4,7,33,35,36,47.56,58,59) The second viewpoint regards the decrease in reflectivity in terms of the decrease in radiant energy as a function of distance into the second medium. (5,6,24,25,27,36,37,39,40,42,57) A depth of penetration (d p ) term is utilized in the discussions associated with both viewpoints of the sampling depth. However, the depth of penetration term has also been defined differently in discussions by various investigators using the same viewpoint of sampling depth.…”

Explicit determination of the complex refractive index of an absorbing medium from reflectance measurements at and near normal incidence

“…A variety of reflectance methods [1][2][3][4][5][6][7][8][9][10][11][12] is available to deter mine the complex refractive index N = n -jk of an absorbing medium. Few of those methods 5,6,9,10 provide explicit solu tions for n and k in terms of the measured reflectances.…”

“…Few of those methods 5,6,9,10 provide explicit solu tions for n and k in terms of the measured reflectances. In this Letter we propose a new method that provides simple, direct, and explicit determination of n and k in terms of the intensity reflectance measured at normal incidence R and the fractional change of such reflectance A3t/3i that results from a given change of angle of incidence from 0 to φ, where φ is a small angle (≲20°).…”

An infrared transmission cell for ultra-thin liquid films

“…In recent studies of the absolute absorption intensities of strongly absorbing materials these difficulties have been circumvented by the use of techniques based on dispersion (2, 3), reflection (4,5), or attenuated total reflection (a.t.r.) measurements (6,7). These methods give an absorption curve only indirectly after considerable computation and, in the case of the reflection and a.t.r.…”