Interchannel interference in multiwavelength operation of integrated acousto-optical filters and switches

Multiple wavelength filtering/switching can be obtained using integrated acousto-optical wavelength filters and switches in LiNbO₃ by driving them with several RF signal simultaneously. As a consequence, interchannel interference occurs due to the interaction of several acoustic waves within the same mode converter resulting in an intensity modulation of the transmitted optical waves. System performance can be degraded as this interchannel interference leads to a power penalty equivalent to an additional cross talk. We present the coupled-mode analysis of the interchannel interference in the multiwavelength operation of acousto-optical filters and switches. Theoretical models are developed and confirmed by experimental results. Furthermore, the impact on WDM system performance is studied by measuring bit error rate characteristics and comparing the results with the theory