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Research On Absolute Distance Measurement Based On Twice Feedback Laser Self-mixing Interference

Posted on:2018-09-26Degree:MasterType:Thesis
Country:ChinaCandidate:R Q ZhengFull Text:PDF
GTID:2348330512992653Subject:Information and Communication Engineering
Abstract/Summary:PDF Full Text Request
The laser self-mixing interference measuring technology is a new optical precise measuring technique formed by taking use of external feedback light which influences the output performance of the laser.With the rapid development of modern photoelectronic technology,optical fiber communications and traditional interference technique,the laser self-mixing interference measuring technology was used widely in such measurements of distance,morphology,displacement,vibration and other parameters.With the development of aerospace and shipbuilding industry,the measurement of absolute distance has been getting broad attention,and the actual requirement of the measurement of high-accuracy absolute distance was proposed.The thesis begins with the laser self-mixing interference theory.The principle of laser distance measuring and the means of chirp were researched as the emphasis,the formation mechanism of multiple feedback laser self-mixing interference was analyzed deeply,and an approach using the secondary feedback laser self-mixing distance measuring from the perspective of the theoretical structure was proposed to effectively deal with the contradiction between measurement accuracy and hardware design in the traditional distance measuring ways.The upgrade of step resolution accuracy and further that of measuring accuracy were realized by taking use of optical distance doubling on the basis of not increasing the complexity of processing circuit through optical signals and the cost.The main researched contents contain:Firstly,the analysis model of the laser self-mixing interference theory was established based on the three-mirror cavity equivalent model and Lang-Kobayashi rate equation.On that basis,the feedback laser self-mixing interference theory was proposed for many times to obtain the relationship between multiple feedback laser self-mixing interference light ware and external cavity light ware wave.Secondly,the theory of the laser self-mixing interference absolute distance measurement was introduced to analyze the frequently-used laser self-mixing distance measuring way by comparison.On that basis,the secondary feedback laser self-mixing distance measuring way was proposed,and the measuring equation based on the secondary feedback laser self-mixing absolute distance measurement was deduced from the laser light intensity..Then,the distance measuring experimental platform of multiple feedback laser self-mixing interference was designed and established,mainly containing the selection of lasers,the utility of laser precision current source and thermostat,data acquisition and processing and others.Finally,the feasibility analysis of the proposed ways was made on the basis of the established experiment platform.
Keywords/Search Tags:multiple laser self-mixing interference, absolute distance measurement, linear frequency modulation
PDF Full Text Request
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