Study On One DBR Er～(3+)/Yb～(3+) Codoped Fiber Laser

In order to enhance the bit rate and well use the bandwidth of 1.55μmwave band in WDM fiber-optic communications technology, the study onlasers of accurate wavelength and excellent performance has alwaysbeen the hot concern of people. The operation wavelength of fiber lasercan be determined by Fiber Bragg Gratings (FBG) precisely. For instance,DBR single frequency Er3+ doped especially Er3+/Yb3+ codoped fiberlasers have been rapidly developed. Yet, till now, there have been fewdomestic reports on Er3+/Yb3+ codoped fiber lasers. The research work isstill at the start. With the continuous miniaturization and integration of future fullfiber-optic component developments, the shorter is the better for thelaser source. In contrast with Er3+-doped fiber lasers, Er3+/Yb3+ codopedfiber lasers can not only simplify the lasers' structure while shorteningtheir size, but can increase the stability and practicability for theircompactness and flexibility. The lasers, with their various advantages,have become one hotspot in full fiber-optic communications system.Therefore, the lasers, as a new laser or information source, have theirsharp competitiveness and promising future. The Er3+/Yb3+ codoped fiber laser put forward in the thesis, with itspump being 1064nm Nd:YAG is the first one ever reported and filled thedomestic blank. The paper integrated the theoretical design and analysisinto the configuration setup and experiment measurement researchmethod. The research contents accomplished can be described asfollows, 861. Put forward the practical design of the DBR Er3+/Yb3+ codoped fiber laser on the basis of analyzing and contrasting various current popular schemes; 2. The technological parameters of the output laser were calculated after large scales of searches, extensive collection of data, prudent theoretical design and the optimization; 3. On the basis of theoretical design, the apparatus and components for the experiment were actively prepared and set up; 4. Optimized the length of the Er3+/Yb3+ codoped fiber and found the fit size of such type of Er3+/Yb3+ codoped fiber; 5. Debugged the experiment and measured the main technological indexes, then verified whether the fiber laser could meet the theoretical requirements. Meanwhile, gave comprehensive appraisal. The 1064nm pump whose model was MIL- Ⅱ was made byChangchun New Industries Optoelectronics Tech. Co., Ltd. Theresonant-cavity was constructed by splicing the FBG1 and FBG2(sharing the same Bragg wavelength, 1551.84nm Rpeak FBG1: 99%,1552.08nm Rpeak FBG2: 60%), to each side of the gain medium — a4.42-meter-long Er3+/Yb3+ codoped fiber. In contrast with the Er3+ onlyDBR fiber laser, the length of the gain medium was significantlyshortened. The broad bandwidth FBG1 and narrow bandwidth FBG2 forthe output were the cavity mirrors. The 1064nm light induced from the1064nm pump's tail fiber was launched into the resonant-cavity via a1064/1550nm WDM, the port1 and port2 of a (1×2, 99/1) 1064/1550nmcoupler and FBG1. And then, a population inversion was formed in the 87Er3+/Yb3+ codoped fiber and the excited light was produced. The outputlaser with needed wavelength could be acquired via the light travelingthrough FBG2 and Dual-ISO. Thus, the DBR Er3+/Yb3+ codoped fiberlaser was constructed. The development of the fiber laser was supported by the Ji LinProvince Technology Development Scheme — The Er3+/Yb3+ codopedfiber laser based on FBGs. The target, main research and developmentcontents of the scheme can be described as follows, 1. Finish the theoretical and structural design of the Er3+/Yb3+ codoped fiber laser based on FBGs, which is made up of a certain length of Er3+/Yb3+ codoped fiber laser, FBGs, and...