光纤耦合声光调制器的理论和实验研究

发布时间：2018-04-15 18:56

本文选题：光纤耦合声光调制器 + 光纤激光器　；参考：《河北工业大学》2015年硕士论文

【摘要】：区别于自由空间调制器,光纤耦合声光调制器具有低插入损耗,结构紧凑,体积小,密封设计,没有可移动部件而可靠性高等优点。随着激光技术和光纤技术的发展,光纤耦合声光调制器凭借着其优异性,正广泛的应用于脉冲光纤激光器,光纤放大器,脉冲采集器等领域中。和传统的半导体激光器相比,光纤激光器具有结构简单,斜率效率好,散热性能优良,输出光束好等优点。本文所要研究的光纤耦合声光调制器是应用于1064nm的10W/20W打标用脉冲光纤激光器中,作为其中的关键调Q器件,它的性能好坏影响着整个脉冲光纤激光器的性能。因此,对光纤耦合声光调制器进行理论和实验方面的研究就有了一定的实际意义。首先介绍了常用的光纤激光器的结构以及光纤耦合声光调制器在其中所起的作用。论述了国内外目前对声光器件以及对光纤耦合声光调制器的研究现状,分析了其中的差距,制定出所要研制的光纤耦合调制器的性能指标。然后,分别从理论和实验方面进行了研究。理论方面:通过分析光纤耦合声光调制器的结构组成,以及声光相互作用的理论,定性地说明了三个主要性能指标的影响因素,并对其进行分析。由于它的独特的结构,还需对两个光纤准直器的耦合效率理论进行研究分析,进行模拟仿真。根据性能指标要求,提出对驱动器的要求,进行方案设计,各个模块的设计,制成电路板并进行测试。实验方面:根据前面对声光互作用理论的分析,给定加载驱动信号的声光晶体。通过实验研究了光纤准直器的光束直径和光束发散角对插损和开关时间的影响,选取合适的用于耦合的光纤准直器。最后,对于给定的声光晶体,加载驱动信号,选取光束直径为375um,光束发散角为2.3mrad的光纤准直器,对光纤耦合声光调制器进行测试,得到插入损耗为2.3dB,光脉冲上升时间为60ns,消光比达到49dB,达到了设计指标,应用到脉冲光纤激光器中,性能良好。
[Abstract]:Different from free space modulator, optical fiber coupling acousto-optic modulator has the advantages of low insertion loss, compact structure, small size, sealed design, no movable parts and high reliability.With the development of laser technology and optical fiber technology, fiber coupling acousto-optic modulator is widely used in pulsed fiber laser, fiber amplifier, pulse collector and so on.Compared with conventional semiconductor lasers, fiber lasers have the advantages of simple structure, good slope efficiency, excellent heat dissipation and good output beam.The fiber coupling acoustooptic modulator is used in 1064nm 10W/20W marking pulsed fiber laser. As a key Q-switched device, its performance affects the performance of the whole pulse fiber laser.Therefore, the theoretical and experimental study of optical fiber coupling acoustooptic modulator has certain practical significance.Firstly, the structure of fiber laser and the function of fiber coupling acoustooptic modulator are introduced.The present research status of acoustooptic devices and optical fiber coupling acousto-optic modulators at home and abroad is discussed. The gap between them is analyzed and the performance indexes of the fiber optic coupling modulators are worked out.Then, the theoretical and experimental studies are carried out respectively.In theory: by analyzing the structure of optical fiber coupling acousto-optic modulator and the theory of acousto-optic interaction, the influencing factors of three main performance indexes are explained qualitatively and analyzed.Because of its unique structure, the coupling efficiency theory of two optical fiber collimators should be studied and simulated.According to the requirement of performance index, the requirement of driver is put forward, the scheme design, the design of each module, the circuit board and test are made.Experiment: according to the previous analysis of acousto-optic interaction theory, the acousto-optic crystal with driving signal is given.The influence of beam diameter and beam divergence angle on insertion loss and switching time of optical fiber collimator is studied experimentally. A suitable optical fiber collimator for coupling is selected.Finally, for a given acousto-optic crystal, the optical fiber collimator whose beam diameter is 375um and beam divergence angle 2.3mrad is selected to test the optical fiber coupling acousto-optic modulator.The results show that the insertion loss is 2.3 dB, the rising time of optical pulse is 60 ns, the extinction ratio is 49 dB, and the design index is reached. The performance of the laser is good when it is applied to pulsed fiber laser.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN761

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