Abstract: An optical method and apparatus for nondestructively inspecting a specimen for evidence of surface flaws, for example, cracks granularity and/or roughness characteristics, which would be indicative of component expected lifetime before failure are disclosed.The distribution pattern of coherent light scattered by a surface illuminated sample is obtained with a transform lens (for a two-dimensional pattern) or a transform-cylinder lens pair (for a one-dimensional pattern). The surface scattered light distribution is inherently different for flawed and unflawed samples. Spatial frequency signatures obtained from measurements of the scattered light diffraction patterns are used to distinguish flawed from unflawed specimens. Measurements are not restricted to planar surfaces; curved sample shapes can be employed with appropriate optical component adjustments.

Abstract: An optical method and apparatus for noncontacting inspection of a specimen to evaluate quantitatively its surface roughness characteristics are disclosed.The distribution of light scattered by a Gaussian rough surface illuminated with a laser beam is obtained with a transform and cylinder lens pair (for a one-dimensional light distribution), or by a transform lens alone (for a two-dimensional Gaussian light distribution) when no tooling marks, scratches, etc., would mar the surface and mask the measurement. Spatial frequency halfwidths of the optical Fourier transform spectrum of the scattered light are known to be linearly related to the planar surface roughness characteristics. Hence, with appropriate calibration, the measured light distribution halfwidths can be used to evaluate surface roughness. Measurements are not restricted to planar surfaces; curved specimen shapes can be employed with appropriate optical adjustments.

Abstract: A means of probing a biological cell sample with a optical source to determine the characteristics of the cell image by way of measuring parameters from its two dimensional Fourier transform. These techniques lead to a method of measuring discriminating parameters for cell classification.

Abstract: A means of probing a biological cell sample with a optical source to determine the characteristics of the cell image by way of measuring parameters from its two dimensional Fourier transform. These techniques lead to a method of measuring discriminating parameters for cell classification.