The Research Of Tm-doped Fiber Laser And The Optical Fiber Amplifier

The 2 ?m Tm-doped fiber lasers and amplifiers have many applications in medication,laser remote sensing and optical communications.However,it has shown a significant decrease of laser gain near the 2 ?m wavelength for it is close to the cut-off wavelength of the emission of Tm3+ ion,which is detrimental to the WDM systems and future optical communications.To obtain a gain flattening performance of the amplifier in 2?m band,three experiments are proposed to investigate the thulium-doped fiber amplifier,by applying a proper design of configuration and optimized parameters,a gain-flattened optical amplifier near 2 ?m with high power output is experimental demonstrated.At first,the advantages of developing silicon-based optical fiber lasers,the importance of tunable Tm-doped fiber lasers,and the research progress on 2 ?m fiber lasers and amplifiers at home and abroad are introduced.Then,the energetic structure of Thulium ions and the cross-relaxation(CR)and energy up-conversion(ETU)processes between energy levels were explored,which proves the ability of generating 2 ?m band lasering in the silicon glass based Tm-doped fiber laser(TDFL).And then three pumping methods and cladding-pumped method are introduced.Among the experiments.Firstly,a 1560 nm fiber grating-based high-power laser is developed to amplify the seed ligh,after comparative experiments and optimization,a stable output of 1W at 1560 nm is achieved,and the laser signal-to-noise ratio performance is good.Secondly,a 2 ?m Tm-doped tunable fiber lasers is proposed,based on the ring cavity and the wavelength selection of the F-P cavity filter,the laser wavelength tunable from 1870 to 2040 nm is finally achieved.Finally,a set of amplifier structures are designed to improve the gain flatness in the 2 ?m long band,it is realized by implementing a 1560 nm pump to backward pump the TDF as the 1 st-stage amplifer and a 793 nm to forward pump the TDF as the 2nd-stage amplifier,after optimizing the configurations and the gain fiber length,the amplifier performance of a flat gain of 28± 1.3 dB at a wavelength of 1960-2040 nm range and a gain of 28 ± 1.3 dB is realized under a total pump power of 6W.In case OdBm of signal light at 2000 nm is injected to the two-stage amplifier,a laser output of 0.91 W and a slope efficiency of 15.2%is achieved.