Erbium Doped Fiber Design For The Amplification of The Orbital Angular Momentum Modes

Abstract

The technology, “Mode-Division Multiplexing (MDM),” is gaining interest to over come the challenge of high capacity of data transmission through a single optical fiber. The vortex light modes having helical phase-fronts are the new rising candi dates for achieving efficient MDM. They act as the different orthogonal channels for data transmission through fiber. However, to achieve long-distance communi cation based on OAM modes, the role of fiber amplifier for amplifying the OAM modes is indispensable. The two designs of photonic crystal fiber are proposed in this thesis, which can be used as erbium-doped fibers (EDFs) and can am plify large number of OAM (Orbital Angular Momentum) modes. The theoretical modelling of PCF based EDFA shows that at 1550nm wavelength, 20 OAM modes (l = 5,6,7,8,9) are amplified simultaneously, and a gain of more than 20 dB is achieved for both the designs with DMG less than 0.15 dB. Moreover, for the range of wavelengths (1535nm-1565nm), all the 20 modes at each wavelength are also amplified simultaneously with gain excursion less than 2 dB and DMG less than 0.2 dB.