Simultaneous Measurement of MDL and DMGD in FMFs by Analyzing the Rayleigh Backscattering Amplitudes

Abstract

In this paper, we propose and experimentally demonstrate a novel method for simultaneously measuring mode-dependent loss (MDL) and differential modal group delay (DMGD) in few mode fibers (FMFs). This method is based on analyzing the Rayleigh backscattering amplitudes obtained with a special nondestructive measurement system. With this method, the MDL and DMGD in about 9.8 km 3-mode fiber are successfully measured, which are 0.186 dB and 3.581 ps/m between LP01 and LP11a and 0.157 dB and 3.604 ps/m between LP01 and LP11b, respectively. Then, the experimental results of DMGD and MDL with different methods are compared, which show that the values of DMGD and MDL obtained by the proposed method agree well with that using the time-of-flight (TOF) and conventional transmission methods, respectively. In addition, it is also demonstrated that the proposed scheme can be scalable to measure FMFs with a large number of modes.