半导体激光正弦相位调制干涉测振技术的研究
文献类型：学位论文
| 作者 | 李中梁 |
| 学位类别 | 博士 |
| 答辩日期 | 2009 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 王向朝 |
| 关键词 | 振动测量 干涉测量 光学检测 正弦相位调制 |
| 其他题名 | Study on laser-diode sinusoidal phase-modulating interferometry for vibration measurement |
| 中文摘要 | 随着精密加工技术的飞速发展，机械部件微小振动的高精度测量日益受到人们的重视。振动测量不但可以用于机械结构动态特性分析、机械系统的故障诊断和振动源的测量等方面，而且在消除噪声中也发挥着重要的作用。半导体激光正弦相位调制干涉测振技术作为国际上先进的准外差干涉测量技术，具有测量精度高、调制方便、结构简单等优点，在振动测量领域得到了广泛的研究。本论文针对该技术在实际应用中存在的不足之处，提出具体的解决方法，从理论和实验上验证这些方法的可行性和实用性；并将该技术成功应用到硅微机械谐振传感器研究和加速度测量领域。主要工作包括以下几个方面： 1．通过注入电流调制半导体激光器波长的同时，激光器的输出光强也被调制，对测量精度造成影响。本文对已有的消除光强调制影响的方法进行分析，针对其存在的问题，提出两种新方法。分别通过干涉仪中参数的优化选择和归一化系数的求解实现光强调制影响的消除。与已有方法相比，这两种方法不需要附加其他元件，干涉仪结构简单；采用容易实现的实时相位检测器对干涉信号进行处理，实现物体微小振动的高精度实时测量，测量的重复精度达到1nm。 2．利用正弦相位调制菲索干涉仪测量振动时，由于菲索板及待测物体表面对入射光的多次反射容易产生多光束干涉，引入一定的测量误差。本文以纳米精度微小振动测量为应用背景，以多光束干涉信号强度随相位的分布规律为基础，通过分析多光束干涉引入的算法误差，提出一种减小多光束干涉影响的方法。该方法在对干涉仪调制深度优化的基础上，采用误差补偿的方法，使多光束干涉产生的影响有效减小。 3．针对硅微机械谐振传感器研究领域中已有的单光源激振测振方法的不足，将正弦相位调制干涉测振技术引入到单光源激振测振的相关研究中，提出一种单光源激振测振新方法。该方法采用全光纤结构，利用正弦相位调制技术纳米精度的测量出谐振器的振动曲线；在信号处理过程中通过归一化算法省去一些难以获得准确数值的工作参数的计算。此外，详细分析该方法中由于激振与测振同时实现引入的谐振器振动幅度的测量误差，并讨论减小该误差的方法。实验测得微悬臂梁结构样品的频率响应曲线、谐振频率及其在谐振状态下的振动曲线，测量样品谐振振幅的重复精度小于2nm。 4．以正弦相位调制干涉测振技术为基础，结合“高精度光纤重力加速度计”科研项目，研发一种高精度光纤加速度测量技术。该技术根据加速度测量的基本原理，将待测加速度转化为传感头中膜片的振动，利用正弦相位调制干涉仪高精度的测量此振动，即可得到待测加速度。在理论和实验研究的基础上，研发一台高精度光纤加速度计样机，并对其进行性能测试。该样机经过长城计量测试技术研究所的测试，达到以下指标：测量范围±1g；响应频率0～1Hz；分辨率10-5g/Hz ；精度10-4g/Hz ；工作温度范围0～55℃。 5．作为半导体激光正弦相位调制干涉测振技术的扩展研究，结合“高精度长距离测量技术”科研项目，研发一种利用半导体激光线性调频干涉仪实现绝对距离测量的技术。该技术采用三角波注入电流对半导体激光器进行线性调频，通过“粗测”与“细测”相结合的方法实现绝对距离的测量。粗测采用对干涉信号进行条纹计数的方法；细测通过傅立叶变换的方法提取相位信息，得到最终的测量结果。该技术采用全光纤结构，并利用参考技术，具有较强的抗干扰能力。实验证明利用该技术可以在300mm的范围内实现绝对距离的测量，重复性小于3μm。 |
| 英文摘要 | With the rapid development of precision-machining technology, the micro-vibration of mechanical component becomes an important system attribute. Much attention has been focused on the measurement of micro-vibration with ultra-high accuracy. Micro-vibration measurement plays an important role in many fields, such as dynamic characteristics analysis and failure diagnostics for mechanical structures, vibration source identification and noise elimination. Laser diode sinusoidal phase-modulating interferometry is an advanced pseudo-heterodyne measurement technique. The technique has the merits of high precision, convenient modulation manner, and simple system configuration. So, it has been widely studied in the field of vibration measurement. However, there are still some critical imperfections in the technique which influence the system performance. In view of these imperfections, several novel methods are presented in this dissertation. The feasibility and practicability of the methods are demonstrated both theoretically and experimentally. The laser diode sinusoidal phase-modulating interferometry is also applied in a silicon micromechanical resonant sensor and an acceleration sensor successfully. The main work of this dissertation is as follows. i. In a laser-diode (LD) sinusoidal phase-modulating interferometer, the wavelength of the LD is sinusoidally modulated by varying its injection current. However, the intensity modulation is associated with the wavelength modulation, which becomes one of the main error sources of the measurement system. The existing methods for eliminating the influence of intensity modulation are analyzed. In view of their shortcoming, two new methods are presented. In the first method, the interferometer parameters are optimized. In the second method, a normalized coefficient calculation algorithm is presented. No additional components are required in the two proposed methods. As a real time phase detection module is used, high precision micro-vibration measurement is realized. The structure of the interferometer is simpler.The measurement repeatability reaches 1nm. ii. In a Fizeau interferometer using sinusoidal phase modulation technique, multi-beam interferences are produced due to the multi-reflections between the reference plate and the surface under test. The multi-beam interferences lead to measurement errors of micro-vibration, which are not negligible when nanometer measurement accuracy is needed. The relationship between multi-beam interference intensity and optical path difference (OPD), and the measurement error caused by multi-beam interference are analyzed in detail. Based on the analysis, a new method for reducing the influence of multi-reflection interference is proposed for micro-vibration measurement. The sinusoidal phase modulating depth of the Fizeau interferometer is optimized and the measurement results are compensated The influence of multi-beam interference is reduced effectively. iii. In view of the disadvantage of the existing exciting and detecting methods of vibration in the field of silicon microresonator sensor, a novel method for excitation and detection of vibration using sinusoidal phase modulation interferometry is proposed. A single laser diode is used for excitation and detection, and an all-fiber Fizeau interferometer is applied. The vibration curve of the microresonator is measured with nanometer accuracy. A normalized algorithm is developed to avoid the calculation of some system parameters, which are difficult to obtain true values. Moreover, measurement errors of the vibration amplitude of the microresonator caused by simultaneous excitation and detection of vibration are analyzed. In the experiments, the resonance frequency, vibration waveform and frequency-response curve of the microcantilever sample are measured accurately. Measurement repeatability of the vibration amplitude in resonance is less than 2 nm. iv. A high-accuracy fiber acceleration sensor is developed based on sinusoidal phase modulating interferometry. The sensor transforms the acceleration under test into a displacement of a diaphragm in the sensing head. The displacement is measured using an all fiber sinusoidal phase modulating interferometer. The acceleration is obtained with high accuracy. On the basis of theoretical and experimental study, a prototype of acceleration sensor is developed. The performance of the prototype is tested. Measurement range, responsive frequency, resolution and accuracy of the prototype are ±1g, 0～1Hz, 10-5g/Hz , and 10-4g/Hz , respectively. The operation temperature range is 0～55℃. v. As an extended study of the laser diode sinusoidal phase-modulating interferometry, an absolute distance measurement technique based on laser diode linear-frequency-modulating interferometry is developed. The linear frequency modulation is realized by injecting a triangular wave current into laser diode. The absolute distance is obtained by dividing the measurement result into integer and fractional parts. The two parts are obtained by “coarse measurement” and “fine measurement”, respectively. Coarse measurement is realized by interference fringe count, and fine measurement by phase extraction based on Fourier tranform. The interferometer is with an all-fiber structure. A reference interferometer is introduced to improve its anti-disturbance ability. The measurement repeatability of 3μm is obtained in a measurement range of 300mm. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15257]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 李中梁. 半导体激光正弦相位调制干涉测振技术的研究[D]. 中国科学院上海光学精密机械研究所. 2009. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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