Studies On Multi-Quantum-Well Laser And Er～(3+) Doped Fiber Laser

In this dissertation, theoretical and experimental studies of two kinds of laser foroptical communications are presented. First, multi-quantum-well laser is discussed;Er3+ doped fiber laser is the mainly content. Both of them are the most important lightsource in optical communication system, this dissertation give a lot of meaningfulstudies in this field.Several aspects were carried out as follows: Build carrier density and photon density rate equation about injectedsemiconductor laser, the theoretical model is set up. Using numericalcalculation, linear relationship and logarithmic relationship of optical gainand carrier density are considered respectively, by comparison we findlogarithmic relationship is much better. And we also analyze how the currentand the quantum well number affect the transient response. Set up an mechanism adjustment for external laser, design a direct currentbias voltage regulator, realize feedback by mirror and grating to makeexternal laser, get a spectral widths of 5nm and 2nm. With grating rotation,make the wavelength tuning over of 80nm. Derive a theoretical model of ring cavity fiber laser. Analyze the effect onlaser's output characteristics gave by cavity loss and coupler's outputefficiency. Confirm the relationship between EDF' length and the outputpower and threshold power. In experiment, when coupler's output efficiency is 10%,20%,50%,80%,90% respectively, we get the laser's corresponding output data. With FBG,we realize dual-wavelength and triple-wavelength operation.In this dissertation, theoretical studies, numerical calculations and experimentalstudies are the main work. Some significant results are achieved. So that it lays thefoundation for light source technology development and scientific research in thisfield.