Fast single-mode characterization of optical fiber by finite-difference time-domain method

Usually, although not always, manufacturers producing optical fiber state that the functioning will be single mode in most cases without specifying the wavelengths to be worked with. A rapid method of light simulation within the optical fibers was developed for a single-mode characterization, which avoids errors and problems in transmitting the signals through the fiber. The method was validated with two optical fibers, in which the intensity patterns are well known in theory, and a rather good fit between the theoretic intensity curves at the endface of the fibers was achieved. In order to characterize the monomodal regime, the method was applied to two optical fibers with different refractive-index profiles, using the finite-difference time-domain (FDTD) for the body of revolution (BOR)