Calibration Method for Measuring Structural Parameters of Few-mode Multi-core Fiber

For the parameter measurement of the fabricated few-mode multi-core fibers (FM-MCFs), the accuracy cannot be guaranteed due to the power coupling among each core or each mode in these fibers. In this paper, using the sensitivity of the differential mode delay (DMD) and inter-core skew (ICS) to the relative refractive index difference between each layer and cladding, we compare the simulated DMD and ICS with the measured values to get the range of relative refractive index difference. Assisted by the image processing algorithm, the core diameter and core pitch of FM-MCF are also corrected. This correction method can give a more accurate parameter selection range for FM-MCF, so as to provide data support for FM-MCFs in transmission and sensing fields.