Study On Er:YAG Injection-locked Solid State Laser

Real-time, reliable atmospheric wind field data is an effective evidence for weatheranalysis and prediction of global climate change. Coherent Doppler Lidar (CDL) is themost potential and promising method in atmospheric wind field initiative detection. Thelaser emission source as the most important component of CDL, Not only singlelongitudinal, narrow linewidth, high frequency stability properties, but also high enoughsingle pulse energy and sufficient pulse width are in requirement of CDL laser emissionsource to ensure the distance and the accuracy of the detection. At present, injectionlocking technique employed in the solid state laser is one of the preferred process toobtain CDL laser technology.1.6μm lasers have become the primarily light source ofCDL due to the outstanding properties such as eye safety, less atmospheric absorptionexcellent atmospheric transmission feature. The output wavelength of Er:YAG laser is1.6μm, this thesis study on injectiong-locked Er:YAG laser, injection locked lasercontains master laser, slave laser.For the master laser, on the basis of study on the physical characteristics andspectral characteristics of the Er:YAG crystal, we design two kinds of singlelongitudinal mode laser as the seed laser, one is Er:YAG single longitudinal laser byinserting two F-P, the other is Er:YAG nonplanar ring oscillator (NPRO). A theoreticalanalysis on the dual F-P etalons method is discussion,and building a mathematicalmodel. Single longitudinal mode laser is achieved. Then we introduce the NPRO theory,and higher single longitudinal mode laser is obtained. Then we choose the NPRO as theseed laser.For the slave laser, the method of ring cavity designing is discussed. The thermallens of the Er:YAG is measured, then we design the ring cacity of Er:YAG slave laser.Using the Q-switched rate equation model, we investigate the laser energy extractioneffiency and laser pulse width as well as the main factor of the influence on them. Onthe basis of the study, the output performance of the slave laser is discussed.For the injection-locked, based on the classical theory of light interaction, theinfluence by injected seed laser on the initial light field distribution in the laserresonator is discussed. The effect of seed laser frequency detuning on injection lockingof lasers is analyzed. On the basis study above, we designed the coupling system, andachieved the injection-locked laser output of Er:YAG.