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Theoretical And Experimental Studies On Continuous Wave Polarization-Maintaining Yb3+-Doped Fiber Amplifier

Posted on:2020-02-10Degree:MasterType:Thesis
Country:ChinaCandidate:R R JiFull Text:PDF
GTID:2428330599459149Subject:Precision measuring physical
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The Center for Gravitational Experiments,School of Physics,Huazhong University of Science and Technology?HUST?is conducting research on space-borne laser system for the inter-satellite laser ranging project,which is of great importance for satellite gravity measurement and gravitational wave detection in aerospace.For the high-precision and long-distance inter-satellite ranging experiment,the loss problem during laser transmission must be considered,therefore a high power laser system is required.At present,the main laser structure of high-power space-borne lasers use the so-called master oscillator power amplifier?MOPA?.For the laser ranging using 1064 nm lasers,the MOPA configuration we adopt consists of a narrow linewidth solid-state laser and a Yb3+-doped fiber amplifier.The solid-state laser produces a seed signal with low noise,narrow linewidth,and excellent beam quality.The Yb3+-doped fiber amplifier then amplifies the signal light emitted by the solid-state laser.The development of such a space-borne laser system is essential to the laser precision measurement projects in aerospace.This thesis aims to build a high power Yb3+-doped fiber amplifier.Studies from both theoretical and experimental aspects have been carried out.The thesis mainly includes:the introduction of development background of high-power erbium-doped fiber amplifier,the theoretical basis of double-clad Yb3+fiber amplifier,numerically analysis and designing of the amplification characteristics of fiber amplifier,building and testing of the amplifier experimentally and the conclusion and output of this thesis.After introducing the theory for the numerical simulation of fiber amplifiers,we simulated the Yb3+-doped fiber amplifier using a MATLAB program.Considering the influence of amplified spontaneous emission?ASE?noise in the fiber,we design a two-stage fiber amplifier:the pre-amplification and the power amplification.A narrow-bandwidth fiber filter was inserted after the pre-amplifier and before the power amplifier to suppress the effect of ASE.Based on the simulation results,we designed and built a continuous-wave fiber amplifier.When the power in the fiber is too high,stimulated Brillouin scattering?SBS?may appear.The returned Stokes light will degrade the performance of the amplifier.For our amplifier,we have carried out theoretical and experimental studies.No clear SBS was observed during the experiment,which is in agreement with our theoretical investigation.Additionally,we set up a temperature control system to control the temperature of the gain fiber in the power amplification stage to reduce the temperature effect on the fiber amplifier.
Keywords/Search Tags:ytterbium doped fiber amplifier, narrow linewidth laser, laser ranging, stimulated Brillouin scattering
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