A new method for determining the optical rotatory dispersion of transparent crystalline layers

Twins in YAl3(BO3)4 and K2Al2B2O7 Crystals as Revealed by Changes in Optical Activity

“…Our approach of measuring the optical rotation angle as a function of wavelength shares some similarities with recently reported methods that are either based on channeled spectra recorded using a spectrophotometer with crossed polarizers [40,41] or that employ a motorized rotatable analyzer followed by a transmission grating to disperse the light onto a linear CCD array for simultaneous detection over a range of wavelengths [42]. Here, we combined the high spectral resolution and wide spectral range of the spectrophotometer with the high angular precision provided by polarization scans.…”

Birefringence of Thin Uniaxial Polymer Films Estimated Using the Light Polarization Ellipse

“…In this arrangement the ordinary ray from one anisotropic thin piece becomes extraordinary ray in the second one. In this case the total phase difference between the ordinary and extraordinary rays emerging from the anisotropic layer, expressed in (11), is proportional to the difference in the thicknesses L 1 and L 2 of the polymer pieces composing AL, measured on the light propagation direction.…”

“…In this table, the angles α and θ and the flux densities measured along the semi axes of the rotated ellipse are noted, for a given PVA polymer foil. The values of the phase differences for various azimuth angles were computed with formula (8) and the birefringence can be computed using relation (10) for a single polymer foil, or relation (11) when the AL is composed by two polymer foils with crossed optical axes. The average value of the phase difference from the last column of Table 1 gives a value of birefringence of about 0.0023 for a thickness of the layer of 50 µM.…”

“…The last two materials have the advantage that their birefringence can be modified by external field of forces [1,2]. There are some methods for determining both linear [3][4][5][6][7][8] and circular [9][10][11][12][13] birefringence of the anisotropic layers, based on the compensation of the optical path length [3][4][5][6][7][8][9][10][11][12][13][14][15] or interferometric means [3,8,10]. For thick anisotropic layers the method based on channeled spectra [3,10,12] is usually applied.…”

Optical Rotatory Dispersion of Poly(propylene oxide) in Benzene Solution Determined from Channeled Spectra

“…The method of channeled spectra, initially applied to crystalline, [12][13][14] anisotropic polymer foils [15] or to thin layers of liquid crystals [16,17] in order to determine the linear birefringence, was extended to polymer solutions [18] for estimation optical rotatory dispersion. This is a fast and efficient method to characterize the anisotropy of the transparent layers.…”