IEEE Photonics Journal (Jan 2017)
Generation of the First-Order OAM Modes in Ring Fibers by Exerting Pressure Technology
Abstract
We have proposed an effective method of generating the first-order orbital angular momentum (OAM) modes in ring fibers. The first-order OAM modes (L = ±1) can be represented as the linear superposition of the HE21even mode and the HE21odd mode. Through exerting pressure on the ring fiber by a leverage device, the fundamental mode HE11 can be coupled into higher order mode HE21in broadband wavelength ranging from 1530 to 1600 nm. By adjusting the fiber polarization controller and the pressure value exerted on the fiber, both the positive (L = +1) and negative (L = - 1) OAM modes can be generated separately. Moreover, we have demonstrated that the coupling efficiency from the fundamental mode to the first-order OAM modes at wavelength of 1550 nm can reach 67%.
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