Research On HiBi Fiber Sagnac Rings For Gain Flattening And Comb Light Sources

Recently, HiBi optical fiber Sagnac rings attracted more and more attentions due to their nearly perfect comb filtering nature and the potential applications in fabricating various high performance optoelectronic devices and modules for WDM systems. In this thesis, the mechanism of the spontaneous and stimulated emissions in Erbium doped fibers (EDFs) are analyzed and the optical properties of HIBi fiber Sagnac rings with single or multiple sections are studied theoretically and experimentally, Based on which, the optical properties of power flattening and comb light sources composed by HiBi fiber Sagnac Ring and EDF were numerically studied in details. The major works of this thesis are summarized as follows:1). Based on deeply analyzing, it is obtained that HiBi Sagnac ring can be served as a perfect comb filter due to its high side-mode suppression ratio, polarization insensitive, easy to adjustment. Meanwhile, multi-section HiBi fiber Sagnac rings also can be used as gain or ASE flattener.2). A theoretical model and the corresponding simulation programs for the analysis of Erbium doped fibers were established based on Er³⁺ rate-equations and optical power traveling-wave equations. Almost all the emission properties of the EDFs under various parameters and conditions were numerically analyzed and disscused.3). A general theoretical model and the corresponding simulation programs for multi-section HiBi fiber Sagnac rings was developed by employing the Jones matrix method, Based on which, the optical properties of HiBi fiber Sagnac rings were numerically studied in very details.4). Based on the above results, a kind of optical power flattened multi-wavelength comb-like light sources composed of two HiBi fiber Sagnac rings, one is single section and another is two section, were analyzed and numerically studied.The numerical results show that the power flattened multi-wavelength comb-like light sources have important potential applications in multi-wavelength fiber sensing systems and mid to low bit-rate, short distance WDM fiber communication systems.