Chromatic dispersion measurement of optical fiber using spectroscopic optical coherence tomography

Abstract

Chromatic dispersion (CD) in optical fibers results in the broadening and overlapping of transmitted lights, and thus reduces the capacity of information transmission and increases the bit-error-rate of communication system. Hence it needs to be accurately measured and then compensated. There have been various methods for fiber CD measurement, but most of them are complicated to obtain wavelength components and require adjustment during measurement, and thus have the drawbacks of being time-consuming, and susceptible to system stability and environmental influences. In this work, a measurement method of fiber CD based on the principle of spectroscopic optical coherence tomography (OCT) was proposed by using a swept-source OCT system to capture interference signal, and using Wigner-Villy distribution as time-frequency analysis method to extract spectral − spatial distribution. Wavelength − OPD curve could be obtained from the distribution, where the OPD (optical path difference) is the spatial delay induced by the fiber CD, and the CD profile varying with the wavelength was finally obtained from the curve. One fiber sample was measured with 1060 and 1310 nm band systems, and another different type of fiber sample was measured with 1310 nm band system. The measured results are agreement with the claimed or theoretical results, demonstrating the feasibility of this method. It has some significant advantages and is a promising method for fiber CD measurements.