Showing papers on "Total external reflection published in 1981"

Refraction of a surface polariton by an interface

Abstract: By means of a normal-mode analysis, transmission and reflection coefficients have been calculated for a surface polariton crossing a plane boundary at normal incidence from one surface-active medium to another. The energy radiated into the vacuum above the two surface-active media has also been calculated.

Refractive index temperature sensor

Abstract: An optical temperature sensor and method of manufacture therefor in which the intensity of light reflected from a first dielectric interface or from first and second dielectric interfaces, wherein one of the dielectrics has a temperature dependent index of refraction is measured. The intensity of light refleted from such dielectric interfaces will vary depending on the index of refraction which in turn is temperature dependent, thus providing a temperature dependent light signal.

Evaluation of reflection interference contrast microscope images of living cells

Abstract: Reflection contrast microscope methods are generally used for studies of those portions of the cell that are turned towards the glass coverslip, to comprehend the structure of the cytoskeleton and the dynamics of cell movement, as well as formation of cell-glass contacts. In incident illumination only reflected light contributes to picture formation. The intensity of which in the case of observation of unstained cells is small because of small refraction differences. To overcome this problem a reflection contrast system was developed by Leitz according to Ploem [49], in which by using contrast preserving measures the reflection becomes prominent in comparison with the lens reflexes. The emerging pictures are a result of interferences of reflections at glass-cell, cell-culture medium and culture medium-cell interfaces. According to Fresnel's equations the reflected intensity depends on the differences of the particular refractive indices and the thickness of the layers, which determine the phase of interfering beams. In idealized systems of thin films the reflected intensity is a measure for their optical constants. Relative reflection measurements from glass-cell areas is comparison with the known glass-medium reflection, can therefore be revealing as far as refraction index, cell-glass distance or cell thickness are concerned. The estimates by Bereiter-Hahn et al. [15] were made in the assumption of vertical illumination neglecting its actual conical shape: the comparison of two Fresnel functions of cytological relevant measurements show - in accordance with Gingell and Todd [24] - that this is only permitted under certain conditions, depending on the required accuracy of the measurements; an incidence angle of about 30 degrees leads to an error of about 10%, an angle of 50 degrees to more than 50%.

Refractive index switchable display cell

Abstract: A display cell having at least two states of different opacity, comprises a first material having a first index of refraction, a second material dispersed within the first material and having a second index of refraction, the difference between the first and the second indices of refraction being variable over a range of values, and means for varying the difference in index of refraction over a portion of the range. When the indices of refraction of the first and second material are substantially the same, the display is substantially transparent. Otherwise it is opaque or substantially less transparent.

Heat-ray reflecting film

Abstract: PURPOSE:To obtain a heat-ray reflecting film which reflects efficiently a heat- ray, and has good transmittivity of a visible beam, by laminating alternately a high refractive index layer and a low refractive index layer which are specified, on a substrate. CONSTITUTION:The first film 1 whose optical film thickness is about lambda/8 (lambda is design wavelength) or 3lambda/8 thick is laminated on a glass substrate G, and thereafter, as for the second layer through the (2u+2)-th layer, a lambda/4 alternate layer is laminated, also a film having lambda/8 thickness is laminated on said layer, and when a refractive index of the first layer, a refractive index of the substrate and a refractive index of the second layer are denoted as n1, ng and n2, respectively, ng