Amplifying Orbital Angular Momentum Modes in Ring-Core Erbium-Doped Fiber

Abstract

<jats:p>Lots of research efforts have been devoted to increase the transmission capacity in optical communications using orbital angular momentum (OAM) multiplexing. To enable long-haul OAM mode transmission, an in-line OAM fiber amplifier is desired. A ring-core fiber (RCF) is considered to be a preferable design for stable OAM mode propagation in the fiber. Here, we demonstrate an OAM fiber amplifier based on a fabricated ring-core erbium-doped fiber (RC-EDF). We characterize the performance of the RC-EDF-assisted OAM fiber amplifier and demonstrate its use in OAM multiplexing communications with OAM modes carrying quadrature phase-shift keying (QPSK) and quadrature amplitude modulation (QAM) signals. The amplification of two OAM modes over four wavelengths is demonstrated in a data-carrying OAM-division multiplexing and wavelength-division multiplexing system. The obtained results show favorable performance of the RC-EDF-assisted OAM fiber amplifier. These demonstrations may open up new perspectives for long-haul transmission in capacity scaling fiber-optic communications employing OAM modes.</jats:p>

Generation, Transmission and Application of Orbital Angular Momentum in Optical Fiber: A Review

“…Overall, there is a lot of room for improvement in fiber-based OAM transmission and generation systems. At the same time, the fiber system has great potential for OAM mode support [80][81][82][83][84].…”

Mode-bases gain difference for Different phase profiles in Few-mode Erbium-doped Fiber Amplifiers

“…The collimator lens was used to couple the coaxial beam to the FM-EDF, and the end of the FM-EDF was angle-cleaved by 8°to suppress any undesired influence of the parasitic laser. 39 The DM is used at the output end to filter out the remaining pump, 40 and the signal light is divided into two through beam splitters (BS). On the one hand, an objective lens (Obj) is used to couple the amplified signal demodulated by the phase plate (PP) into a single-mode fiber and then connected to an optical spectrum analyzer (OSA) through a single-mode fiber for recording after the amplification spectrum is obtained.…”

Generation, Transmission, and Amplification of OAM Modes in the PbSe-Doped Ring-Core Fiber Carrying 3D Printed Spiral Phase Plate

“…It was found that the vector modes of the fiber were HE 11 , TM 01 , HE 21 , TE 01 , HE 31 , EH 11 , HE 41 , EH 21 , HE 51 , EH 31 , HE 61 , EH 41 , HE 71 , and EH 51 . The OAM modes supported by the RCF can be generated by linear superposition of odd and even modes of HE modes and EH modes, which can be defined as [25]:…”

“…Therefore, it is necessary to realize the OAM mode amplification. Typically, an erbium-doped fiber is used to achieve high mode gain, low loss, and low DMG [24][25][26]. However, erbium ions have a small gain bandwidth and a fixed working band that fail to satisfy the communication demands.…”