METHOD FOR THE MEASUREMENT OF THE DIAMETER OF A GLASS FIBER USING THE RESONANT BACKSCATTER TECHNIQUE AND MEASURING APPARATUS FOR CARRYING OUT THE METHOD

摘要

A method of measuring the diameter of a glass fiber using the backscattering technique resonance. The fiber to be measured is illuminated by a laser beam of wavelength tunable and the extreme values ​​of the detected intensity of the backscattered rays from the fiber in an acute solid angle are recorded while allowing the wavelength of the laser. The paths of light rays and scattered rays are separated. The illumination laser beam of suitable measuring device for carrying out this process subtends an acute angle with the normal of the fiber axis and the intensity detector receives the backscattered rays is positioned so that the main direction of the rays that accepts an angle of the same magnitude but opposite sign with the said normal. Before the detector is placed a slit of a size corresponding to the full acute angle.