COMPUTER-AIDED VARIABLE WAVELENGTH FOURIER-TRANSFORM POLARIZING MICROSCOPY OF BIREFRINGENT FIBERS

An automatic fringe analysis is used to measure the spectral dispersio n of birefringence of cylindrical textile fibers The approach presente d is based on the optical Fourier transform microscopy of birefringent fibers. The pattern of the optical Fourier transform observed in a po larizing microscope is processed automatically to measure the radius o f interference dark fringes as a function of light wavelength. This me thod allows us not only to calculate the interference orders and the s pectral dispersion of birefringence of fibers but also to detect their optical and geometrical microdefects. The image is processed with a c omputer-controlled automatic analysis system. Examples of applying thi s method to highly oriented fibers are given.