Research Of Optical Fiber Measurement By Near-field Method

The development of the fiber technology has promoted more and more use of fiber in the different fields such as fiber communication,fiber sensors, where more requirements are proposed for the optical fiber quality and performance. Thus a better method is needed to measure the optical fibers. Hence, some researches have been done based on the comparison of different measurement methods and measurement equipment. The work is as follows:1,The recommended method, near field method is applied to measure the geometric parameters of single mode optical fiber and multimode fiber (such as the max and min diameter of core, the max and min diameter of cladding, non-circularity of core and cladding, the concentricity relative error of core and cladding, the concentricity absolute error of core and cladding). And the factors impacting measurement is also analyzed.2,The relation between the diameter of single mode optical fiber and multimode fiber is deduced according to related theory and the diameter of mode field is measured.3,The Refractive-index Profile formula of single mode optical fiber and multimode fiber is obtained using the near field method and also measured.4,Based on the propagation-mode near-field method of digital image processing technology, a set of software measuring the geometrical characterization of optical fibers is developed using LABVIEW.5,The measurement automation of optical structural parameters is realized with the near field measuring apparatus of the geometrical characterization of optical fibers and near-field measuring light source.6,SMF-28 G652 fiber, 62.5/125 multimode fiber are measured by this system .