Evolution and systems impact of coherent distributed multipath interference

We demonstrate an emulator that captures the coherent distributed nature of multipath interference in few-mode fiber devices. Coherent interference in these devices manifests in slow power fluctuations as well as relative intensity noise. Slow bit-error-rate drifts and attendant systems power penalty drifts, in timescales similar to the slow power fluctuations (similar to10 s), are the dominant manifestations of this impairment.