Versatile MDM-OFDM system with selectable single-mode half-subcarrier or two-mode full-subcarrier multiplexing

We propose a novel all-optical hybrid MDM-OFDM system that enables variable transmission capacity by seamlessly switching between two-mode full subcarriers and single-mode sparse subcarriers multiplexing through the use of power loading. The operation depends on the mode crosstalk present between the arrayed waveguide grating and the two-mode fiber. Through rigorous analysis, our results indicate that for the two-mode full subcarrier multiplexing, a power loading of 0.78 dB for the TE10 mode guarantees uniform performance across all subcarriers. Furthermore, by effectively suppressing the TE10 mode using a power loading of 12 dB, our system achieves similar performances and functionality to single-mode sparse subcarrier multiplexing, wherein only the TE00 mode is utilized. Our system offers variable transmission rates for data center connections, using all-optical signal processing, without varying the modulation scheme and the symbol rate.