Abstract
We propose long-haul space-division-multiplexing (SDM) transmission systems employing parallel multiple-input multiple-output (MIMO) frequency-domain equalization (FDE) and transmission fiber with low differential mode delay (DMD). We first discuss the advantages of parallel MIMO FDE technique in long-haul SDM transmission systems in terms of the computational complexity, and then, compare the complexity required for parallel MIMO FDE as well as the conventional time-domain equalization techniques. Proposed parallel MIMO FDE that employs low baud rate multicarrier signal transmission with a receiver-side FDE enables us to compensate for 33.2-ns DMD with considerably low-computational complexity. Next, we describe in detail the newly developed fiber and devices we used in the conducted experiments. A graded-index (GI) multicore few-mode fiber (MC-FMF) suppressed the accumulation of DMD as well as intercore crosstalk. Mode dependent loss/gain effect was also mitigated by employing both a ring-core FM erbium-doped fiber amplifier and a free-space optics type gain equalizer. By combining these advanced techniques together, we finally demonstrate 12-core × 3-mode dense SDM transmission over 527-km GI MC-FMF without optical DMD management.
Original language | English |
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Journal | Journal of Lightwave Technology |
Volume | 34 |
Issue number | 1 |
Pages (from-to) | 196-204 |
ISSN | 0733-8724 |
DOIs | |
Publication status | Published - 2016 |
Bibliographical note
Post-Deadline paper.Keywords
- Differential mode delay (DMD)
- Few-mode fiber (FMF)
- Frequency-domain processing
- Multicore fiber (MCF)
- Space division multiplexing