Crosstalk due to optical demultiplexing in subcarrier multiplexed systems

We report an in-depth investigation of the inter-modulation crosstalk in subcarrier multiplexed (SCM) systems with optical demultiplexing (ODeMux). Both theoretical derivations and numerical simulations show that the crosstalk in ODeMux systems mainly comes from the nonlinear mixing of the baseband and subcarrier modulations inside the signal channels. Several key parameters are then studied to estimate their effects on the magnitude of the crosstalk. As a result, performance optimization strategies are proposed for ODeMux SCM systems.