Mode-division multiplexed transmission of wavelength-division multiplexing signals over a 100-km single-span orbital angular momentum fiber

TLDR

The study experimentally demonstrates mode‑division multiplexed transmission using eight orbital angular momentum modes over a single 100‑km low‑attenuation, low‑crosstalk ring‑core fiber. Each OAM mode carries 10 C‑band wavelength‑division multiplexing channels, each transmitting 16‑GBaud QPSK, and the low inter‑mode crosstalk allows the system to rely only on 4×4 MIMO processing, enabling scalability without added signal‑processing complexity. The system achieves an aggregate capacity of 2.56 Tbit/s, a spectral efficiency of 10.24 bit/(s·Hz), and a capacity‑distance product of 256 Tbit/s·km, the highest reported for OAM fiber communications to date.

Abstract

We experimentally demonstrate mode-division multiplexed (MDM) transmission using eight orbital angular momentum (OAM) modes over a single span of 100-km low-attenuation and low-crosstalk ring-core fiber (RCF). Each OAM mode channel carries 10 wavelength-division multiplexing (WDM) signal channels in the C band, with each WDM channel in turn transmitting 16-GBaud quadrature phase-shift keying signal. An aggregate capacity of 2.56 Tbit/s and an overall spectral efficiency of 10.24 bit/(s · Hz) are realized. The capacity-distance product of 256 (Tbit/s) · km is the largest reported so far for OAM fiber communications systems to the best of our knowledge. Exploiting the low crosstalk between the OAM mode groups in the RCF, the scheme only requires the use of modular <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"><mml:mrow><mml:mn>4</mml:mn><mml:mo>×</mml:mo><mml:mn>4</mml:mn></mml:mrow></mml:math> multiple-input multiple-output processing, and it can therefore be scaled up in the number of MDM channels without increasing the complexity of signal processing.