-
激光外差干涉测量是非接触振动探测的重要手段, 随着探测目标距离拓展, 人们对激光测振仪能量利用率和测量分辨力提出了更高的要求. 基于菲涅耳衍射积分、光纤耦合等相关理论, 建立了收发一体式光纤激光测振仪光场传递模型, 并基于散粒噪声受限假设, 提出粗糙目标回光情况仪器噪声基底评价方法. 结果表明, 收发望远镜焦距和口径共同决定系统能量利用率分布情况, 并进一步影响仪器测量分辨力. 针对激光波长为1550 nm, 光纤模场半径为5 μm, 对准距离为1 km的典型应用场景进行数值仿真实验, 收发透镜最优F数为3.3, 验证了模型的正确性, 仿真结果可作为光纤激光测振仪、激光测风雷达等收发镜头设计的依据.
In a laser Doppler vibrometer (LDV), the laser Doppler effect is used to real-time acquire target displacement, velocity, and acceleration. Fiber optic laser vibrometers have received widespread attention in recent years due to their strong environmental adaptability and high integration advantages. With the expansion of detection target distance, higher requirements have been put forward for the measurement resolution of laser vibrometers. The LDV system typically employs a transceiver integrated telescope structure for laser emission and target return light reception. The aperture and focal length of the transceiver telescope determine its basic structure, directly affecting the emission and reception efficiency of laser energy. Additionally, the speckle effect generated by the scattering of rough targets affects the coupling of light energy entering the fiber optic for interference, thereby influencing the LDV measurement resolution. Based on relevant theories such as Gaussian beam waist transmission, rough target generation, Fresnel diffraction integration, and fiber optic coupling, a transceiver integrated fiber optic laser vibrometer optical field transmission model is established. Numerical simulation and analysis of the emission transmission process of ideal Gaussian laser and the coupling process of surface target echo reception are conducted. Based on the assumption of laser vibrometer speckle noise limitation, an evaluation scheme for the instrument’s noise baseline under rough target return light conditions is proposed. Numerical simulation experiments are conducted for a typical fiber LDV application scenario with an alignment distance of 1 km, a single-mode fiber mode field radius of 5 μm, and a laser wavelength of 1550 nm. The results indicate that the focal length and aperture of the transceiver telescope determine the distribution of system energy utilization and further affect the instrument’s noise baseline. Simulation results show that when the F-number of the transceiver lens reaches 3.3, LDV achieves the highest system energy utilization at this focal length, verifying the correctness of the simulation model. The simulation results can serve as a basis for the design of transceiver lenses for fiber optic laser vibrometers, laser anemometers, and other devices. -
Keywords:
- laser Doppler effect /
- wave propagation /
- speckle /
- fiber coupling
-
图 1 典型激光外差振动测量系统原理图
Fig. 1. Schematic diagram of a typical laser heterodyne vibration measurement system.
图 2 焦距600 mm, 口径200 mm情况下光强和相位分布 (a) 光纤内部光强; (b) 光纤内部相位; (c) 发射过程D面光强; (d) 发射过程D面相位; (e) 接收过程D面光强; (f) 接收过程D面相位; (g) 接收过程A面光强; (h) 接收过程A面相位
Fig. 2. Intensity and phase distribution under the condition of a lens focal length of 600 mm and a diameter of 200 mm: (a) Intensity inside fiber; (b) phase inside fiber; (c) intensity on D plane during the emission process; (d) phase on D plane during the emission process; (e) intensity on D plane during the receiving process; (f) phase on D plane during the receiving process; (g) intensity on A plane during the receiving process; (f) phase on A plane during the receiving process.
图 3 透镜焦距600 mm, 口径200 mm情况下系统能量利用率概率分布图
Fig. 3. Probability distribution diagram of system energy efficiency under the condition of a lens focal length of 600 mm and a diameter of 200 mm.
图 4 粗糙目标不同透镜参数下评价因子$\sigma $分布曲线
Fig. 4. Distribution curve of evaluation factor $\sigma $ for rough target under different lens parameters.
图 5 镜面目标不同透镜参数下评价因子$\sigma $分布曲线
Fig. 5. Distribution curve of evaluation factor $\sigma $ for specular target under different lens parameters.
表 1 激光发射传输过程说明表
Table 1. Explanation table of laser emission transmission process.
状态/过程 光场分布表示 理论基础 近似条件 A $ {U_{{\text{A, TX}}}}(x, y) $ 单模光纤光场分布理论 光纤高斯光场分布假设 A→B $ {U_{{\text{B, TX}}}}(x, y) $ 高斯光束自由空间传输理论 傍轴近似 B→C $ {U_{{\text{C, TX}}}}(x, y) $ 透镜相位调制理论 理想薄透镜假设
理想圆孔硬边光阑假设C→D $ {U_{{\text{D, TX}}}}(\xi , \eta ) $ 菲涅耳衍射积分理论 傍轴近似 
下载: 导出CSV
表 2 激光回波接收耦合过程说明表
Table 2. Explanation table of laser echo reception coupling process.
状态/过程 光场分布表示 理论基础 近似条件 D $ {U_{{\text{D, RX}}}}(x, y) $ Johnson转化系统理论 粗糙表面平稳随机过程假设 D→C $ {U_{{\text{C, RX}}}}(x, y) $ 菲涅耳衍射积分理论 傍轴近似 C→B $ {U_{{\text{B, RX}}}}(x, y) $ 透镜相位调制理论 理想薄透镜假设
理想圆孔硬边光阑假设B→A $ {U_{{\text{A, RX}}}}(x, y) $ 菲涅耳衍射积分理论 傍轴近似 光纤耦合 — 光纤耦合理论 —
下载: 导出CSV
表 3 不同目标不同焦距对应口径和F数拐点比较
Table 3. Transition points of aperture and F-number corresponding to different focal lengths for various targets.
收发透镜焦距 镜面目标 粗糙目标 口径/mm F数 口径/mm F数 400 mm 105 3.81 120 3.33 500 mm 130 3.84 155 3.22 600 mm 155 3.87 185 3.24 700 mm 180 3.89 210 3.33
下载: 导出CSV
-
[1] Peng R, Xu B, Li G, Zheng C, Li X 2018 IEEE 23rd International Conference on Digital Signal Processing Shanghai, China, November 19–21, 2018 p1
[2] 程傒 2021 硕士学位论文 (哈尔滨: 哈尔滨工业大学)
Cheng X 2021 M. S. Thesis (Harbin: Harbin Institute of Technology
[3] 李彦超, 章亮, 杨彦玲, 高龙, 徐博, 王春晖 2009 物理学报 58 5473
Google Scholar
Li Y C, Zhang L, Yang Y L, Gao L, Xu B, Wang C H 2009 Acta Phys. Sin. 58 5473
Google Scholar
[4] Shang J, He Y, Wang Q, Li Y, Ren L 2020 Sensors 20 5801
[5] 刘翠红, 臧朝平, 张根辈 2021 航空动力学报 36 477
Liu C P, Zang C P, Zhang G B 2021 J. Aerospace Power 36 477
[6] 陈鸿凯 2020 硕士学位论文 (北京: 中国科学院大学)
Chen H K 2020 M. S. Thesis (Beijing: University of Chinese Academy of Science
[7] 杜召杰 2017 硕士学位论文 (淄博: 山东理工大学)
Du S J 2017 M. S. Thesis (Zibo: Shandong University of Technology
[8] 李斐斐, 吴谨, 赵志龙, 王东蕾, 叶征宇, 于彦明 2012 强激光与粒子束 24 2549
Google Scholar
Li F F, Wu J, Zhao Z L, Wang D L, Ye Z Y, Yu Y M 2012 High Power Laser and Particle Beams 24 2549
Google Scholar
[9] 王小林, 周朴, 马阎星, 马浩统, 李霄, 许晓军, 赵伊君 2011 物理学报 60 084203
Google Scholar
Wang X L, Zhou P, Ma Y X, Ma H T, Li X, Xu X J, Zhao Y J 2011 Acta Phys. Sin. 60 084203
Google Scholar
[10] Dräbenstedt A 2014 AIP Conference Proceedings Ancona, Italy, May 27, 2014 p263
[11] Iverson T Z, Watson E A 2017 Laser Radar Technology and Applications XXII Anaheim, CA, United States, May 5, 2017 p108
[12] Rzasa J R, Cho K, Davis C C 2015 Appl. Opt. 54 6230
Google Scholar
[13] Ruilier C, Paris O D 2007 Proc. SPIE 3350 319
[14] Winzer P J, Leeb W R 1998 Opt. Lett. 23 986
Google Scholar
[15] 孔新新, 张文喜, 才啟胜, 伍洲, 戴玉, 相里斌 2020 物理学报 69 190601
Kong X X, Zhang W X, Cai Q S, Wu Z, Dai Y, Xiang L B 2020 Acta Phys. Sin. 69 190601
[16] 晏春回, 王挺峰, 张合勇, 吕韬, 吴世松 2017 物理学报 66 234208
Google Scholar
Yan C H, Wang T F, Zhang H Y, Lü T, Wu S S 2017 Acta Phys. Sin. 66 234208
Google Scholar
[17] 刘德明, 孙军强, 鲁平, 孙琪真, 夏历2008 光纤光学 (北京: 科学出版社) 第103页
Liu D M, Sun J Q, Lu P, Sun Q Z, Xia L 2008 Fiber Optics (Beijing: Science Press) p103
[18] 周炳琨, 高以智, 陈倜嵘, 陈家骅 2009 激光原理 (北京: 国防工业大学) 第70页
Zhou B K, Gao Y Z, Chen T R, Chen J H 2009 Principles of Laser (Beijing: National Defense Industry Press) p70
[19] 季小玲, 吕百达 2003 物理学报 52 2149
Ji X L, Lü B D 2003 Acta Phys. Sin. 52 2149
[20] 波恩 M, 沃尔夫 E著 (杨葭荪译) 2019 光学原理 (北京: 电子工业出版社) 第343页
Born M, Wolf E (translated by Yang J S) 2019 Principles of Optics (Beijing: Publishing House of Electronics Industry) p343
[21] 邓慧, 张蓉竹 2014 强激光与粒子束 26 121009
Google Scholar
Deng H, Zhang R Z 2014 High Power Laser and Particle Beams 26 121009
Google Scholar
[22] 方兆本, 缪柏其 2011 随机过程 (北京: 科学出版社) 第80页
Fang Z B, Miao B Q 2011 Random Process (Beijing: Science Press) p80
下载:
计量
- 文章访问数: 280
- PDF下载量: 5
- 被引次数: 0
