2μm相干测风激光雷达的双平衡外差探测技术研究

发布时间：2018-05-25 05:15

本文选题：双平衡外差探测 + 噪声抑制　；参考：《北京理工大学》2015年硕士论文

【摘要】：风速测量是气候学的重要项目之一,提高风速测量的精度,对火箭发射、飞机的起飞和着陆,以及军事装备应用等方面都具有重要的意义。双平衡外差探测系统是在平衡探测系统的技术基础上,具有稳定的环境适应能力和优良的信噪比表现,同时可实现信号光的强度、频率、相位、偏振的高精度解调,在相干激光雷达、相干光通信、外差干涉领域具有广泛应用价值。双平衡外差探测系统的研制,对于提高2μm相干测风激光雷达的探测灵敏度具有重要意义。本文的主要工作有:1.对双平衡外差探测系统进行了原理介绍,使用矩阵光学的方法建立了双平衡外差探测器的数学模型,推导了双平衡相干探测系统的信噪比公式,通过数值仿真对平衡外差探测与一般相干探测进行比较,从理论上证明了双平衡外差探测系统在消除本振相对强度噪声、提高信噪比上的优越性。2.使用OptiSystem光通信仿真软件搭建了双平衡探测系统模型,代入实际器件的参数进行仿真试验,仿真验证了双平衡探测系统在解调信号光振幅、频率、相位和偏振度的可行性。3.分析了实际情况下造成平衡探测器两支路电流不等的成因,数值模拟了调节支路中的衰减系数对信噪比的影响,通过OptiSystem仿提出并确定了优化方案和最优化参数。4.从准直失配角和光程差不等两个角度,分析了双平衡外差探测系统中的空间失配问题,得出了双平衡探测系统虽然对光程差的偏差不敏感,但对准直失配角十分敏感的结论,从原理上指出了系统零件加工工艺和组装精度的重要性。5.在原有双平衡外差探测结构的基础上,提出了新型光纤式双平衡外差探测结构图,并使用OptiSystem仿真软件进行了系统搭建和仿真,仿真验证了新型光纤式双平衡外差探测结构的可行性。结合市场调研,介绍了适用于本研究的新型特种光纤器件,为光纤式双平衡外差探测奠定了基础。
[Abstract]:Wind speed measurement is one of the important climatology items. Improving the accuracy of wind speed measurement is of great significance to rocket launch, aircraft take-off and landing, and military equipment application. The dual balance heterodyne detection system is based on the technology of balance detection system, and has a stable environment adaptability and good signal to noise ratio. It can realize the high precision demodulation of the intensity, frequency, phase and polarization of the signal light. It has wide application value in the field of coherent laser radar, coherent optical communication and heterodyne interference. The development of the dual balance heterodyne detection system is of great significance for improving the detection sensitivity of the 2 m coherent wind lidar. The main work of this paper is 1.: the principle of double balance heterodyne detection system is introduced. A mathematical model of double balance heterodyne detector is established by using matrix optics, and the signal-to-noise ratio formula of the dual equilibrium coherent detection system is derived. Through numerical simulation, the equilibrium heterodyne detection is compared with the general coherent detection, and the double equilibrium heterodyne detection is proved theoretically. The measurement system can eliminate the relative intensity noise of the local oscillator and improve the superiority of the signal to noise ratio..2. uses the OptiSystem optical communication simulation software to build a dual balance detection system model and substituting the parameters of the actual device to carry out the simulation test. The simulation verifies the feasibility of the dual equilibrium detection system to demodulate the amplitude, frequency, phase and degree of polarization of the signal..3. The cause of the difference in the current of two branches of the balance detector is analyzed. The influence of the attenuation coefficient on the signal to noise ratio is numerically simulated. The optimization scheme and the optimization parameter.4. are proposed and determined by OptiSystem imitation, and the dual balance heterodyne detection system is analyzed by the two angles of the collimation and light path difference. In the problem of space mismatch, it is concluded that the dual equilibrium detection system is not sensitive to the deviation of the optical path difference, but it is very sensitive to the straight mismatch angle. The importance of the processing technology and assembly precision of the system parts is pointed out in principle.5.. On the basis of the original dual balance heterodyne detection structure, a new type of optical fiber type double balance heterodyne is put forward. The structure and Simulation of the system are built and simulated with OptiSystem simulation software. The feasibility of the new optical fiber type double balance heterodyne detection structure is verified by simulation, and a new special fiber device suitable for this study is introduced with the market research. It lays the foundation for the detection of optical fiber type double balance heterodyne.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P412.2;TN958.98

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