能量差分干涉测量技术研究

【作者】 陶海敏；

【导师】 庄其仁；

【作者基本信息】 华侨大学 ， 光学， 2008， 硕士

【摘要】 本论文以He-Ne激光为光源,研究了等厚干涉仪和马赫-曾德尔干涉仪(M-Z干涉仪)分振幅干涉中的光能量分配特性,由此得到能量差分干涉条纹曲线。利用干涉仪光能量分配的变化特性研究其应用,提出采用连续改变干涉光场接收面积从而获得光场能量变化曲线的能量差分干涉测量技术,理论和实验验证了这种干涉测量方法对消除光本底噪声和机械震动影响的作用与效果。理论分析了平板等厚干涉中透射光场和反射光场的光能量随两平板表面夹角的变化特性。计算结果表明,两表面夹角α越大,反射光场和透射光场的光能量变化越小,当α足够大时能量趋于一稳定值。利用这一特性可对干涉测量仪器中的光源功率不稳定和杂散光进行补偿,本文介绍了应用于激光干涉膨胀仪的光能量补偿方法。详细介绍了基于M-Z干涉仪的能量差分干涉测量技术原理,理论推导了激光M-Z干涉仪中两个垂直输出光场的能量分配随两相干光束夹角的变化规律,证明了两垂直输出光场干涉图样具有互补对称性。在此基础上提出能量差分干涉测量方法,通过在M-Z干涉仪的准直装置中加入一个可变光阑,随着光阑孔直径的变化,两垂直输出光场的能量随之改变,将这两个光场的能量进行差分放大,就可以得到与干涉条纹变化周期和相位完全一样的干涉条纹曲线。分析了差分干涉测量技术对背景光和杂散光的消除原理,以及对干涉条纹抖动的积分补偿原理,由于外界的影响会同时引起两幅干涉图像的对称变化,能量差分和积分平均在一定条件下可较好地消除振动的影响。工作中的主要创新点:1、提出一种基于M-Z干涉仪的能量差分干涉测量方法。2、与常规干涉测量不同,探测或处理的干涉条纹不是局部的信号,而是整个干涉场的光能量,从而提高了探测灵敏度。3、利用M-Z干涉仪两输出光场的互补特性,采用差分放大的信号输出作为干涉条纹波形,消除了本底光信号,具有很高的条纹信号对比度。4、能量差分干涉测量方法在一定条件下可较好地消除机械振动引起的干涉条纹抖动影响。更多还原

【Abstract】 This paper includes a energy differential interference fringe curve by analysing energy distribution character in amplitude interferometer and M-Z interferometer with the He-Ne laser as light source, by which an interferential energy distribution curve has been obtained. Such a curve could be used as an interference differential interferometry, in which the receiving area have been changed in order to obtain the energy changing curve. The fact that interference optical measurement can effectively eliminate background noise and vibration influence has been demonstrated by theory and experiment.The changing character of reflective energy and refractive energy , which vary with the angleα, has been analyzed (αis the angle between the two plates). The results show that the change of reflective energy and refractive energy lessens asαincrease and it tend to be steady whenαis large enough. The character can be used to compensate unstable source and stray light in interferometer. This paper introduces the compensation used in laser interference dilatometer.The energy differential interferemetry principle based on M-Z interferometers has been introduced in detail,a conclusion that the energy of the two vertical output optical interference fringe change with the angle between two beams is derived, and also the paper approves that they are complementary symmetry. Based on this principle, an energy differential interferometry is proposed. If a variable diaphragm is added into collimating device of M-Z interferometer, the energy of the two output vary with radius, a interference fringe curve with the same phrase and the same period has been obtained by making differential amplifier on this two optical energy.Back light and stray light can be erased by this kind of differential interference measurement, it also can make integral representation to flutter fringe. Since the external disturbances could influence the symmetry properties of the two symmetry interferogram. Energy differential interferometry and integral average can cancel shake’s influence effectively under certain condition.Main innovation point :1. Introducing a energy differential interferemetry measurement based on M-Z interferometers2. Differ from the general interferometry, the detected or treated fringe is the entire energy of optical interference field rather than the partial energy of interference fringes.3. Taking difference amplifier output wave as fringe wave on the basis of symmetry of the two output in M-Z,. Ground noise is erased, fringe contrast is proved.4. Energy difference interferometry can dramatically erase fringe wave bounce provoked by shake.更多还原