In-service crosstalk monitoring in multicore fibers based on precoded DMT system.

Abstract

In-service crosstalk monitoring based on the precoding technique in a discrete multitone (DMT) system is proposed and validated experimentally. The method relies on the ability of time-frequency domain equalization of precoded DMT. Experiments on a 20 GBaud 16 quadrature amplitude modulation DMT system over seven-core weakly coupled multicore fibers (MCFs) are conducted. The inter-core instantaneous average crosstalk (IAXT) is gathered and evaluated in a period as short as 10 µm without disturbing the signal transmission. Such IAXT has a high correlation with the bit error ratio (BER), and a transmission performance evaluation strategy of the MCF transmitting system is developed according to the relationship between IAXT and BER.