Abstract

Spatial division multiplexing (SDM) can support the capacity demand increase in short-range optical link, but the communication is affected by the intermodal crosstalk. In order to target a low-cost energy-efficient solution, we propose to exploit direct modulation and direct detection without MIMO post-processing in a mode division multiplexed (MDM) system. We theoretically analyze the frequency distribution of the crosstalk contributions taking into account that directly modulated sources at the same nominal wavelength are actually characterized by a certain frequency shift. Our model demonstrates that this shift originates a non-uniform beating noise in the frequency domain due to the intermodal crosstalk. We propose to exploit discrete multitone modulation and a guard band in the multicarrier spectrum to cope with the non-uniform crosstalk issue for typical crosstalk values due to present commercial multi-plane light conversion MUX/DEMUX devices and propagation in few few-mode fiber (FMF) kilometers. The model is validated by comparing simulations and experimental results in the case of a 2-mode MDM system. We demonstrate in a pure SDM scenario that, with respect to single mode transmission, the capacity can be increased of 2.3 times in a 10-km FMF link with 4-modes exploiting direct detection, limited-bandwidth directly modulated lasers and commercial mode MUX/DEMUXs.

© 2019 IEEE

PDF Article

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription