A novel MUX/DEMUX based on few-mode FBG for mode division multiplexing system

• A novel mode MUX/DEMUX has been proposed, which is realized by the few-mode fiber Bragg gratings (FBG) combined with the optical circulator.
• Our proposed MUX/DEMUX has the advantages of low-modal-crosstalk, simple structure, relatively stable, easy to achieve and to couple with the fiber link.
• A 2×10 Gbps MDM transmission over 10 km two-mode fiber is experimentally demonstrated. And if the crosstalk of the FMF is low, the MDM transmission with error-free performance can be achieved with no need of complex digital signal processing (DSP) technique in the receiver side by our proposed MUX/DEMUX.

In this paper, a novel mode multiplexer/demultiplexer (MUX/DEMUX) based on few-mode fiber Bragg gratings (FBG) has been proposed. The principle of the MUX/DEMUX based on few-mode FBG has been described in detail, and crosstalk of better than −20 dB is obtained experimentally. Then a 2×2 division multiplexing (MDM) system has been established with the MUX/DEMUX we proposed. The transmission experiment of 2×10 Gbps PRBS has been achieved successfully, which are carried by LP01 mode and LP11 mode, respectively. When the receiver sensitivity is greater than −14 dB m and −10 dB m, the BER can both reach 10−3 for B2B and 10 km transmission, respectively.