Abstract: This invention provides an optical and computation system that does not utilize moving parts, which enables the angular orientation of the optical axes on the surface of a birefringent material to be determined and comparably, the orientation of the optical axes within light emerging from that surface. Further, since this invention considers the relative orientations of the preferred axis or axes of polarization within light, this method is also applicable for determining the angular orientation of the preferred axis of polarization of elliptically or linearly polarized light or the orientation of the polarizing axis of the material causing the preferred direction of polarization. For birefringent generated axes, this invention allows for the principal axis to be identified distinctly from the quadrature axis and without ambiguity.

Abstract: This invention discloses an optical and computation system that enables the magnitude of the retardation, or the birefringence, in a birefringent material to be measured. This is achieved by consideration of the spectral interference pattern generated by combining quadrature axes of polarized light that have passed through the material, however, unlike other approaches, this invention removes the spectral intensity variations of the light source and the spectral attenuation variations of the optical system before analyzing the resultant spectral interference pattern. Since the spectral interference pattern is unique for each retardation or birefringence value, this invention provides an absolute measure of these quantities.

Abstract: This invention discloses a mechanical stress measurement system which utilizes a birefringent coating and spectral demodulation to determine the magnitude and angular orientation of the stresses in a mechanical element from which the loads acting on that mechanical element are calculated. The invention provides for the measurement of Torque, Axial and Bending loads in a shaft, whether they exist singularly or in combination, without the requirement for electrical, mechanical or physical contact with the shaft, and is able to determine the magnitude and sense of the torque and axial loads, and the magnitude and plane of the bending load.