The Study Of Er-doped Fiber Laser Based On Fiber Ring Resonator

Because there is gain material in the resonator, the active fiber ring resonators show polymorphic characteristics in their different working state. Under the threshold, the active fiber ring resonator can be used as scanning optical spectrum analyzers, optical filters or delay-line and so on. Upper the threshold, the active fiber ring resonator could become the fiber ring laser or fiber ring Cyroscope etc. According to different applications, some varied kinds of material can be implanted into the resonator. And among these structures, the active fiber ring resonator with Erbium-doped fiber pumped by laser diode (LD) is one of the most important ones.Basing on the Erbium-doped fiber ring resonator,Erbium-doped fiber laser was researched theoretically and experimentally, Which include:(1)Gain and output power of EDFL are discussed based on the two energy level modeling method. Some analytical equations of important parameters such as gain, fiber length, erbium concentration, coupling coefficient are derived. The factors that influenced the output of the laser are analyzed theoretically. The output power of the laser is observed to be related with the length of EDF, the coupled-ration of the output coupler and the loss of splicing.We carried out the steady state experiments by employing the existing experiment equipments. The spontaneous-emission spectrum of erbium-doped fiber was measured. We developed an erbium-doped fiber ring laser which the line-width and the output power of this laser are 0.93nm and -1dBm, respectively.(2)The technique of injection locking was analyzed theoretically. The line-with is deduced under this modulation. An injection locking Erbium doped fiber ring laser has been researched experimentally. We gained a laser with the line-width and the output power of this laser being 0.64nm and 2dBm, respectively. Finally, we analyzed the result of the experiment.(3)Thorough analyzed the work principle of the single/double channels Mach-Zehnder (M-Z) fiber interferometer and choosing modes with composite cavity. And we demonstrate experimentally a two-wavelength Erbium-doped fiber ring laser by using a Mach一Zehnder fiber interferometer and composite cavity. As a result, a fiber ring resonator laser with simultaneous two-wavelength oscillations are obtained in room temperature. This device has advantageous of simple design fabrication and low cost et al.