Far-field and near-field methods for optic fiber characterization

Abstract

Optical fibers play an important role in modern technologies. They are largely used both in industrial and civil applications: telecommunications, defense and aerospace, test and measurement, automotive, chemical, and specifically in medical applications. The far-field method gives information about the modal distribution of propagation light an optical fiber, and provides a technique for determining the numerical aperture of optical fiber, and allows identification of the conditions in which a stationary mode distribution has been formed. The near-field technique is a method for determination of the refractive index profile in an optical fiber. Both far-field and near-field methods are used for characterization of optical fibers, which is needed in development of various applications, specifically in development of biochemical and medical fiber optic sensors.