基于光纤叠栅的可调谐掺铒光纤激光器研究

发布时间：2018-08-11 14:33

【摘要】：多波长、可调谐光纤激光器因能够提供多个波长激光同时输出,且可以实现单/多波长激光的可切换、可调谐输出,在光纤通信系统、光纤传感系统、密集波分复用系统等领域具有广泛的应用。多波长、可调谐光纤激光器小型化、集成化已成为未来的发展趋势。光纤叠栅(SIFG)是一种体积小巧的光栅器件,具有波长间隔、反射率的灵活性,对温度、应变响应的敏感性,利于光纤激光器的集成。因此对基于光纤叠栅的可调谐掺铒光纤激光器(EDFL)进行研究具有十分重要的理论价值和实际意义。本文在总结目前多波长、可调谐EDFL的技术和研究现状的基础上,采用耦合模理论分析了光纤布拉格叠栅(SIFBG)的反射谱特性,研究了多波长线形腔EDFL的工作原理,并实验研究了基于SIFBG和啁啾光栅(CFBG)的可调谐EDFL以及基于D-SIFBG(Double-SIFBG)的可调谐EDFL的输出特性。论文的主要内容包括:首先,基于耦合模理论,在光纤光栅满足谐振耦合的条件下,深入研究了光纤SIFBG的特性,对多波长、输出线宽不同和输出波长间隔不同的SIFBG的反射谱进行了数值仿真分析;分析了掺铒光纤的均匀增益特性;重点研究了线形腔EDFL的重要参数,如粒子数反转、增益、激光器的阈值、输出功率、斜率效率等相互间的约束关系;分析了EDFL的模式竞争、多波长EDFL的稳定振荡条件等。其次,基于Giles模型研究了EDFL的工作原理;设计了结构简单、尺寸小、元件少的双波长、多波长SIFBG和CFBG的光纤激光器结构;实验分别研究了基于双波长SIFBG和CFBG的可调谐EDFL的单/双波长可切换、可调谐激光的输出特性,以及基于三波长SIFBG和CFBG的可调谐EDFL的单/双/三波长可切换、可调谐激光输出特性,分析了泵浦功率、谐振腔腔长等对激光输出的影响,分析了出射激光的稳定性等。再次,为了获得线宽更窄、光信噪比更高的激光输出,设计并制备了窄带宽的双波长D-SIFBG和双波长掺铒D-SIFBG,分别用这两种光栅构成线形腔EDFL,实验分别研究了这两种激光器的输出特性,包括泵浦功率、谐振腔长度对出射激光功率等的影响,出射激光的中心波长和输出功率的稳定性以及出射单/双波长激光的波长可切换、可调谐输出特性等。最后,分析了多波长D-SIFBG的特性;实验研究了基于多波长D-SIFBG的单波长可调谐EDFL的输出特性,分析了激光器的单波长可调谐激光输出特性,分析了激光器的输出稳定性等。本文对基于不同光纤叠栅的EDFL的特性进行了较为深入的研究,能够为可调谐EDFL向小型化、集成化方向发展提供有价值的参考。
[Abstract]:Multi-wavelength, tunable fiber laser can provide multiple wavelength laser output at the same time, and can realize single / multi-wavelength laser switching, tunable output, in optical fiber communication system, optical fiber sensing system, Dense wavelength Division Multiplexing (DWDM) systems are widely used in many fields. The miniaturization and integration of multi-wavelength tunable fiber lasers have become the trend in the future. Fiber stacked gate (SIFG) is a compact grating device with the flexibility of wavelength spacing, reflectivity, sensitivity to temperature and strain response, and is conducive to the integration of fiber lasers. Therefore, the study of tunable erbium-doped fiber laser (EDFL) based on fiber stacked gate is of great theoretical value and practical significance. On the basis of summarizing the technology and research status of multi-wavelength and tunable EDFL, the reflection spectrum characteristics of fiber Bragg stacked gate (SIFBG) are analyzed by coupling mode theory, and the working principle of multi-wavelength linear cavity EDFL is studied. The output characteristics of tunable EDFL based on SIFBG and chirped (CFBG) and tunable EDFL based on D-SIFBG (Double-SIFBG) are studied experimentally. The main contents of this paper are as follows: firstly, based on the coupled mode theory, the characteristics of fiber SIFBG are deeply studied under the condition that the fiber grating satisfies the resonant coupling. The reflectance spectra of SIFBG with different output linewidth and output wavelength interval are numerically simulated, and the uniform gain characteristics of erbium-doped fiber are analyzed, and the important parameters of linear cavity EDFL, such as population inversion, gain, are studied emphatically. The constraints of threshold, output power and slope efficiency of the laser are analyzed, and the mode competition of EDFL and the stable oscillation conditions of multi-wavelength EDFL are analyzed. Secondly, the working principle of EDFL is studied based on Giles model, and the structure of fiber laser with simple structure, small size and few components is designed, and the structure of fiber laser with multi-wavelength SIFBG and CFBG is designed. The single / double wavelength switchable and tunable laser output characteristics of tunable EDFL based on dual wavelength SIFBG and CFBG, and the single / one double / three wavelength switchable of tunable EDFL based on three wavelength SIFBG and CFBG are studied respectively. The effects of pump power and cavity length on laser output and the stability of the output laser are analyzed. Thirdly, in order to obtain the laser output with narrower linewidth and higher optical signal-to-noise ratio, A narrow bandwidth dual-wavelength D-SIFBG and a dual-wavelength erbium-doped D-SIFBG are designed and fabricated. The two gratings are used to form the linear cavity EDFLs respectively. The output characteristics of the two kinds of lasers, including pump power, are studied experimentally. The influence of the cavity length on the output laser power, the stability of the center wavelength and output power of the output laser, the wavelength switchability and tunable output characteristics of the single / double wavelength laser, etc. Finally, the characteristics of multi-wavelength D-SIFBG are analyzed, the output characteristics of single-wavelength tunable EDFL based on multi-wavelength D-SIFBG are experimentally studied, the output characteristics of single-wavelength tunable laser are analyzed, and the output stability of laser is analyzed. In this paper, the characteristics of EDFL based on different fiber stacked gates are studied in depth, which can provide a valuable reference for the development of tunable EDFL in the direction of miniaturization and integration.
【学位授予单位】：燕山大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN248

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