高功率光纤激光相干偏振合成系统研究
发布时间：2018-07-18 07:53
【摘要】：受限于光纤本身的热效应、非线性效应、模式不稳定、光纤端面损伤、高亮度泵浦技术等,单路光纤激光亮度提升能力有限。共孔径相干合成技术能获取更高亮度的激光输出。就共孔径相干合成系统而言,其单路高亮度光源的研制和整个合成系统效率的提升是目前相干合成领域的国际难题。本文选取共孔径相干合成技术的一种典型代表-相干偏振合成技术作为研究对象,开展了系统的理论和实验研究。1、综合考虑单频/窄线宽保偏光纤放大器功率提升的两大主要受限因素—受激布里渊散射效应和模式不稳定效应,对实现全光纤结构高亮度、窄线宽、近线偏光纤激光的技术途径进行了详细探索。对比了不同增益介质、不同窄线宽种子放大下的亮度提升潜力与受限因素,研究了引入弯曲损耗机理、减小增益光纤纤芯尺寸、改变泵浦波长等模式不稳定抑制方法的可行性与适用范围;在系统研究的基础上,最终探索得到了实现2 k W级高亮度、窄线宽、近线偏光纤激光输出的技术方案。2、综合考虑实际工程系统中的多种影响因素,对大功率相干偏振合成系统开展了较全面的理论分析和相关实验验证。首先建立了相干偏振合成系统单个合成单元合成效率分析的普适理论模型,分析给出了大阵元合成系统合成效率分析的递推关系,在一定近似条件下给出了多路合成系统合成效率分析的近似表达式。随后,针对大功率相干偏振合成系统的三个重要组成部分—相位与光程控制系统、单元光束、合成元件(光纤端帽、准直器、半波片、偏振合束器),依次开展了详细的理论分析,分析给出了大阵元相干偏振合成系统对上述各种影响因素的容忍度。考虑现有技术条件,分析指出了大功率、多阵元相干偏振合成系统需研究和论证的关键技术问题。分析给出了系统主要影响因素对合成效率影响的工程评价方法,并自行设计实验完成了验证。3、针对高功率、大阵元相干偏振合成系统需论证和解决的关键技术问题开展了较详细的研究。自行设计实验验证了相位控制系统的矫噪能力,自行设计实验测试了高亮度窄线宽保偏放大器的相位噪声分布特性。论证了自主研制高亮度窄线宽保偏放大器用于高功率相干偏振合成系统的可行性,并提出了系统进一步优化的方法。为大功率、多阵元相干偏振合成系统设计了多路精度梯变式光程控制系统,对光程控制系统在复杂光谱下的可行性进行了初步实验验证。在此基础上,对其用于大功率、多阵元相干偏振合成系统的可行性进行了分析说明,提出了进一步优化的方法。设计实验对自行研制的高亮度窄线宽保偏放大器的动态倾斜抖动幅度进行了测试,证明了其能够用于大功率、多阵元相干偏振合成系统。基于高亮度窄线宽保偏放大器,对合成系统中各个元件的热透镜效应进行了测试,分析指出商业化准直系统的热透镜效应将严重限制相干偏振合成系统向高功率、大阵元拓展。为了从根本上克服合成元件热透镜效应对合成效率的影响,从透镜窗口选取、离焦补偿方式选择等方面进行了深入的研究,在研究的基础上联合研制出了大功率离焦补偿性准直系统,并对其离焦补偿精度、补偿范围等重要参数进行了测试,分析论证了其用于大功率、多阵元相干偏振合成系统的可行性。4、构建了高功率相干偏振合成系统实验平台,开展了不同类型、不同功率水平光纤放大器的相干偏振合成实验,论证了合成方案在单频激光、皮秒脉冲激光、窄线宽激光和多波长激光方面的亮度提升能力,通过系统优化不断推动合成方案迈向了新的发展水平。结合理论模型和工程评价方法,对系统输出特性进行了详细分析。以高功率实验结果为参考,分析指明了系统进一步优化的方向,并为相关系统进一步优化的目标提供了理论参考。
[Abstract]:Limited to the thermal effect of the fiber itself, the nonlinear effect, the mode instability, the optical fiber end face damage, the high brightness pumping technology, and so on, the luminance enhancement ability of the single optical fiber laser is limited. The common aperture coherent synthesis technology can obtain the higher brightness laser output. The enhancement of the efficiency of the system is an international problem in the field of coherent synthesis. In this paper, a typical representative coherent polarization synthesis technology is selected as the research object, and the theoretical and experimental study of.1 is carried out. The two major constraints of the single frequency / narrow linewidth preserving optical fiber amplifier are taken into consideration. With the effect of stimulated Brillouin scattering and unstable mode, the technical way to realize high brightness, narrow line width and near line biased optical fiber laser is explored in detail. The potential and limited factors of luminance enhancement under different gain medium and different narrow linewidth seed amplification are compared, and the mechanism of bending loss is introduced, Jian Xiaozeng is introduced. On the basis of the system research, the technical scheme for realizing high brightness, narrow linewidth and near line partial optical fiber laser output of 2 K W is finally explored on the basis of the system research, and a variety of influence factors in the real engineering system are taken into consideration, and the high power coherence is taken into consideration. A comprehensive theoretical analysis and experimental verification are carried out in the polarization synthesis system. First, a universal theory model for the synthesis efficiency analysis of a single synthesis unit in the coherent polarization synthesis system is established. The recurrence relation of the synthesis efficiency analysis of the large array synthesis system is given, and the synthesis system is synthesized under certain approximate conditions. The approximate expression of the efficiency analysis is followed. Then, for the three important components of the high power coherent polarization synthesis system, the phase and optical path control system, the unit beam, the synthetic element (fiber end cap, collimator, half wave, polarization beam splitter), the detailed theoretical analysis is carried out in turn, and the coherent polarization synthesis system of large array element is analyzed and given. The tolerance of the various factors mentioned above. Considering the existing technical conditions, the key technical problems needed to be studied and demonstrated in the high power, multi array element coherent polarization synthesis system are analyzed. The engineering evaluation method of the influence of the main factors on the synthesis efficiency is given, and the self line design experiment has completed the verification of.3 for high power, The key technical problems of the large array coherent polarization synthesis system need to be demonstrated and solved in more detail. The noise correction ability of the phase control system is verified by self design experiment. The phase noise distribution characteristic of the high brightness and narrow line width preserving amplifier is tested by self design experiment. The independent development of high brightness and narrow line width is proved. The feasibility of the large power coherent polarization synthesis system for high power and the method of further optimization of the system are proposed. The multi-channel precision ladder optical path control system is designed for the high-power, multi array element coherent polarization synthesis system. The feasibility of the optical path control system under the complex spectrum is preliminarily verified. The feasibility of the coherent polarization synthesis system for large power and multi array elements is analyzed and illustrated, and a further optimization method is proposed. The design experiment is used to test the dynamic tilt dither amplitude of the self developed high brightness narrow line width preserving amplifier. It is proved that it can be used in the high power, multi array element coherent polarization synthesis system. The thermal lensing effect of various components in the synthetic system is tested by a high luminance narrow line width biased amplifier. The analysis indicates that the thermal lens effect of the commercialized collimation system will severely limit the coherent polarization synthesis system to high power and large array expansion. The selection of the mirror window and the selection of the defocus compensation are deeply studied. On the basis of the research, a high-power defocusing collimating collimating system is developed, and the important parameters such as the defocus compensation precision and the compensation range are tested, and the feasibility of the system is proved to be used for the coherent polarization synthesis system of high power and multi array element. .4, the experimental platform of high power coherent polarization synthesis system is constructed, and the coherent polarization synthesis experiments of different types and different power level fiber amplifiers are carried out. The luminance enhancement capability of the synthetic scheme in single frequency laser, picosecond pulse laser, narrow linewidth laser and multi wavelength laser is demonstrated, and the synthesis is continuously promoted through system optimization. The scheme moves towards the new level of development. Combining the theoretical model and the engineering evaluation method, the output characteristics of the system are analyzed in detail. The results of high power experiment are taken as reference, the direction of the further optimization of the system is pointed out, and the theoretical reference for the further optimization of the related systems is provided.
【学位授予单位】：国防科学技术大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN253
，
本文编号：2131240
[Abstract]:Limited to the thermal effect of the fiber itself, the nonlinear effect, the mode instability, the optical fiber end face damage, the high brightness pumping technology, and so on, the luminance enhancement ability of the single optical fiber laser is limited. The common aperture coherent synthesis technology can obtain the higher brightness laser output. The enhancement of the efficiency of the system is an international problem in the field of coherent synthesis. In this paper, a typical representative coherent polarization synthesis technology is selected as the research object, and the theoretical and experimental study of.1 is carried out. The two major constraints of the single frequency / narrow linewidth preserving optical fiber amplifier are taken into consideration. With the effect of stimulated Brillouin scattering and unstable mode, the technical way to realize high brightness, narrow line width and near line biased optical fiber laser is explored in detail. The potential and limited factors of luminance enhancement under different gain medium and different narrow linewidth seed amplification are compared, and the mechanism of bending loss is introduced, Jian Xiaozeng is introduced. On the basis of the system research, the technical scheme for realizing high brightness, narrow linewidth and near line partial optical fiber laser output of 2 K W is finally explored on the basis of the system research, and a variety of influence factors in the real engineering system are taken into consideration, and the high power coherence is taken into consideration. A comprehensive theoretical analysis and experimental verification are carried out in the polarization synthesis system. First, a universal theory model for the synthesis efficiency analysis of a single synthesis unit in the coherent polarization synthesis system is established. The recurrence relation of the synthesis efficiency analysis of the large array synthesis system is given, and the synthesis system is synthesized under certain approximate conditions. The approximate expression of the efficiency analysis is followed. Then, for the three important components of the high power coherent polarization synthesis system, the phase and optical path control system, the unit beam, the synthetic element (fiber end cap, collimator, half wave, polarization beam splitter), the detailed theoretical analysis is carried out in turn, and the coherent polarization synthesis system of large array element is analyzed and given. The tolerance of the various factors mentioned above. Considering the existing technical conditions, the key technical problems needed to be studied and demonstrated in the high power, multi array element coherent polarization synthesis system are analyzed. The engineering evaluation method of the influence of the main factors on the synthesis efficiency is given, and the self line design experiment has completed the verification of.3 for high power, The key technical problems of the large array coherent polarization synthesis system need to be demonstrated and solved in more detail. The noise correction ability of the phase control system is verified by self design experiment. The phase noise distribution characteristic of the high brightness and narrow line width preserving amplifier is tested by self design experiment. The independent development of high brightness and narrow line width is proved. The feasibility of the large power coherent polarization synthesis system for high power and the method of further optimization of the system are proposed. The multi-channel precision ladder optical path control system is designed for the high-power, multi array element coherent polarization synthesis system. The feasibility of the optical path control system under the complex spectrum is preliminarily verified. The feasibility of the coherent polarization synthesis system for large power and multi array elements is analyzed and illustrated, and a further optimization method is proposed. The design experiment is used to test the dynamic tilt dither amplitude of the self developed high brightness narrow line width preserving amplifier. It is proved that it can be used in the high power, multi array element coherent polarization synthesis system. The thermal lensing effect of various components in the synthetic system is tested by a high luminance narrow line width biased amplifier. The analysis indicates that the thermal lens effect of the commercialized collimation system will severely limit the coherent polarization synthesis system to high power and large array expansion. The selection of the mirror window and the selection of the defocus compensation are deeply studied. On the basis of the research, a high-power defocusing collimating collimating system is developed, and the important parameters such as the defocus compensation precision and the compensation range are tested, and the feasibility of the system is proved to be used for the coherent polarization synthesis system of high power and multi array element. .4, the experimental platform of high power coherent polarization synthesis system is constructed, and the coherent polarization synthesis experiments of different types and different power level fiber amplifiers are carried out. The luminance enhancement capability of the synthetic scheme in single frequency laser, picosecond pulse laser, narrow linewidth laser and multi wavelength laser is demonstrated, and the synthesis is continuously promoted through system optimization. The scheme moves towards the new level of development. Combining the theoretical model and the engineering evaluation method, the output characteristics of the system are analyzed in detail. The results of high power experiment are taken as reference, the direction of the further optimization of the system is pointed out, and the theoretical reference for the further optimization of the related systems is provided.
【学位授予单位】：国防科学技术大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN253
，
本文编号：2131240
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