Study On Erbium-Doped Superfluorescent Fiber Source

In this paper, Erbium-doped Superfluorescent Fiber Broadband Source (ESFS) is investigated in details. The source, having high output power, broad output spectrum and good wavelength stability, has been widely used in fiber-optic gyroscopes, fiber sensor system and fiber communication system, as well as wavelength-division multiplexing (WDM), and the source also needs to be used as the demodulation source of fiber F-B sensor and fiber grating sensor, Here we put the key research on such point.Numerical Simulation of ESFS is the mian part of this thesis. A theoretical model, based on the ratio equation and propagation equation of Erbium-doped fiber (EDF) with 980nm LD pumping, is estalished. The Shooting Method, combined with the Rounge-Kutta method and improved Newton iteration formula, is applied to solve the mentioned model, and it is demonstrated that the simulated results meet goodly with experiment result in single-pass and double-pass configuration ESFS. In single-pass forward configuration, given in the optimal EDF length, there is a maximal forward ouput power, but have not directly relatioship with the backward output spedtrum. In double-pass configuration, the backward output power will be greatly enhanced utilizeing the Amplified Spontaneous Emission (ASE) by fiber reflector, the L-band output spectrum can be exhibited through the way of the forward configuration ESFS with C-band ASE second pumping.In the paper, the detailed information about the ESFS is introduced through reading a great deal of datum about such field. To compare the simulated result with the experiment resulst in single-pass and double-pass configuration, it can found there is a little difference between them, but it still has effectively means for the experiment. Finally, according to the simulated results, a configuration of a double-stage double-pass ESFS with fiber reflecter is designed After considering the influence of Er ions concentration, EDF length and pumping power on the output charactertics of ESFS, a flat C+L-band superflurescent fiber source with 65nm (from 1538nm to 1603nm) flat bandwidth and 9.2mW output power is obtained, and which can be goodly used in the system of Fabry-Perot sensors and fiber grating sensors in our lab.