Research / 2020 / Article / Fig 1

Research Article

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

Figure 1

Conceptual illustration and experimental configuration of an OAM fiber amplifier based on a ring-core erbium-doped fiber (RC-EDF). (a) Concept and principle of the RC-EDF-assisted OAM fiber amplifier which provides relay amplification of multiplexed OAM modes after lossy long-haul fiber transmission. (b) Measured refractive index profile of the fabricated RC-EDF. The inset shows the measured optical microscope image of the fabricated RC-EDF facet. (c) Schematic illustration of the RC-EDF-assisted OAM fiber amplifier. SLM: spatial light modulator; PBS: polarization beam splitter; HWP: half-wave plate; ISO: isolator; QWP: quarter-wave plate; DM: dichroic mirror.