用于显微成像的单根光纤共振型压电扫描器

发布时间：2018-08-12 19:29

【摘要】：为了推动扫描式显微光学成像方法在临床医学应用和生物学研究中发挥更重要的作用,本文围绕单光纤共振型压电扫描器研制过程中的关键科学技术问题展开了深入研究,并系统地论述了该扫描器的原理、方法、技术和应用。突破了单根光纤共振型压电扫描器的当前开发制作过程中所具有的试探性和盲目性,研究了该扫描器的运行机制,确定了该扫描器性能的决定因素,为该扫描器的开发、设计、制作、评估提供了有效的科学指导依据。本文取得的主要研究成果如下： 1)研究了扫描器各部件材料参数对关键形变参数和振动参数的影响,阐明了其间的定量关系。压电方管末端位移与压电片长度的平方成正比；与压电系数成正比；与外加电场成正比；与压电片的宽度和厚度均成负相关。扫描器悬臂振幅与光纤直径的平方成反比,与悬臂长度的开方成反比,与弹性模量的开方成反比。 2)采用耦合场数值仿真模型,研究了扫描器系统的输入输出响应机制。获得扫描器一阶到四十阶模态,确定了振动模态包括弦振动、悬臂振动、方管扭转、方管振动、和纵向缩放,明确了其中悬臂振动可提供有效光学扫描。获取结构在正弦激励下的稳态响应,获得了0-14kHz频谱上前四阶谐振频率的激励使系统产生的响应量。分析扫描器在惯性、阻尼等具有时间后效性因素作用下的行为。获得了螺旋式扫描的50个运动瞬态；获得了李萨如扫描的60个运动瞬态。 3)扫描器的设计实现了针对不同需求的个性化定制。面向在体临床内窥应用,开发了低电压小型化的扫描器,其直径2mm,驱动电压10V峰峰值；面向离体扫描成像应用,开发了具有较高连续性和均匀性的网格式扫描器件,其具有稳定的行扫描速率879Hz和帧速率3Hz；面向非线性光学成像应用,开发了具有较小非线性光学效应和较高采集效率的扫描器件,在52mW功率输出脉宽175fs,封装后探头直径3.5mm,该探头首创采用小尺寸单根光纤共振型压电扫描器驱动350μm直径光纤获得大于1mm振动范围。总之,本文针对显微光学成像系统的应用需求,开展了单光纤共振型压电扫描器的理论与实验研究。讨论了扫描器运行机制的关键问题,提出了完整的实施方案,获得了原型系统并实现了成像应用。本文工作为单根光纤共振型压电扫描器实现更加广泛的应用提供了基础。
[Abstract]:In order to promote the more important role of scanning microscopic optical imaging in clinical medical application and biological research, this paper focuses on the key scientific and technological problems in the development of single fiber resonant piezoelectric scanner. The principle, method, technology and application of the scanner are discussed systematically. This paper breaks through the exploration and blindness in the development and manufacture of single fiber optic resonance piezoelectric scanner, studies the operating mechanism of the scanner, determines the determinant factors of the scanner's performance, and designs the scanner. Production and evaluation provide effective scientific guidance. The main research results obtained in this paper are as follows: 1) the effects of material parameters on the key deformation parameters and vibration parameters of the scanners are studied and the quantitative relationship between them is clarified. The displacement at the end of the piezoelectric square tube is proportional to the square of the length of the piezoelectric plate, proportional to the piezoelectric coefficient, proportional to the applied electric field, and negatively related to the width and thickness of the piezoelectric plate. The amplitude of the cantilever of the scanner is inversely proportional to the square of the diameter of the fiber, the length of the cantilever and the modulus of elasticity. 2) the coupled field numerical simulation model is used. The input and output response mechanism of the scanner system is studied. The first to fortieth modes of the scanner are obtained, and the vibration modes including chord vibration, cantilever vibration, square tube torsion, square tube vibration, and longitudinal scaling are determined. It is clear that the cantilever vibration can provide effective optical scanning. The steady-state response of the structure under sinusoidal excitation is obtained, and the response of the system caused by the excitation of the fourth-order resonant frequency of the 0-14kHz spectrum is obtained. The behavior of the scanner under the action of inertia, damping and other factors with time after-effect is analyzed. Fifty motion transients of spiral scanning and 60 motion transients of Lisaru scanning are obtained. 3) the design of scanner realizes individualized customization according to different requirements. For in vivo clinical endoscope application, a low voltage miniaturization scanner with a diameter of 2 mm and a driving voltage of 10 V peak is developed, and a grid scanner with high continuity and uniformity is developed for the application of in vitro scanning imaging. It has stable line scanning rate 879Hz and frame rate 3Hz. For nonlinear optical imaging applications, a scanning device with small nonlinear optical effect and high acquisition efficiency is developed. When the pulse width of 52mW power output is 175 fs and the diameter of the probe is 3.5mm after encapsulation, the probe is the first to drive 350 渭 m diameter optical fiber with a small size single fiber resonant piezoelectric scanner to obtain a larger vibration range than that of 1mm. In conclusion, the theoretical and experimental study of single fiber resonant piezoelectric scanner is carried out to meet the application requirement of micro optical imaging system. The key problems of the scanner operation mechanism are discussed, and a complete implementation scheme is proposed. The prototype system is obtained and the imaging application is realized. The work in this paper provides a basis for the application of a single fiber optic resonance piezoelectric scanner.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R318.6

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