共查询到20条相似文献,搜索用时 78 毫秒
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报道了光学外差法测量表面起伏精度及横向分辨精度达到0.11nm及4μm。本文采用的是完全共光路外差干涉系统,阐述了它的原理、构造及噪声的影响,并将测量结果与其它商品仪器测量结果作了比较。 相似文献
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针对光电极值法和石英晶振法各自的弊端,结合两种方法提出了光控-晶控膜厚监控法.在相同工艺条件下,分别使用这三种方法监控905nm窄带滤光片(规整膜系)和830nm截止滤光片(非规整膜系)的膜厚,对制备的滤光片的透射率光谱曲线进行比较.结果表明,光控-晶控膜厚监控法除了各项指标都符合要求外,在曲线通带处获得的平均透过率值比光电极值法和石英晶振法获得的平均透过率值提高了3%~6%,且与理论光谱基本吻合,光谱特性最好.该方法不仅对规整和非规整膜系都能进行监控,且能有效降低膜厚误差,提高光谱特性. 相似文献
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激光外差干涉测量技术是微振动探测的重要手段,随着微纳应用的拓展,人们对精密测量系统的相位检测灵敏度提出了更高的要求.传统提高测量灵敏度的方法有优化外差干涉系统方案、改进相位重建算法和降低关键器件噪声等.本文提出了一种多光束混合干涉的相位增强方法,经过理论推导和实验验证得到如下近似条件:校正光与信号光的初相位相差πrad情况下,两光束的功率越接近,系统对目标的弱振动振幅响应越大.实验设计的两光束功率相差1%时,观察到了最大146倍的增强效果,该方法在微振动物体高灵敏度测量上具有较大的应用价值,在现有器件指标和相位解调算法不变的基础上可大幅提高外差干涉测量系统的探测能力. 相似文献
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提出了一种新型的基于Savart偏光镜的外差式偏振干涉成像光谱技术,该技术在偏振干涉成像光谱仪中引入一对平行偏振光栅对,使其得到的干涉图频率与波数相关,具有了波数外差的特点,降低了干涉图频率,从而可利用较少的采样点数实现很高的光谱分辨率.对外差式偏振干涉成像光谱技术的基本原理进行了研究,详细分析了系统光程差、干涉图表达式、光谱分辨率以及光谱复原方法等.最后给出了外差式偏振干涉成像光谱仪的设计实例并进行了计算机仿真模拟,所复原的光谱与输入光谱曲线相符合,验证了方案的正确性.外差式偏振干涉成像光谱仪具有结构紧凑、光通量高、稳定性强、光谱分辨率高的特点,尤其适合超小型高稳定性、高探测灵敏度的高光谱探测应用. 相似文献
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针对外差干涉的微振动测量存在稳定性低、严重受环境噪声影响等缺点,提出了对光路的改进方案。根据差分原理将其改为双光路,消除环境噪声的干扰;通过偏振分光棱镜(PBS)将椭圆偏振光变为线偏光,提高干涉信号幅值;改进频移装置(AOM),抑制频率漂移;增加光阑,滤除杂散光,提高系统信噪比。通过探测5 kHz压电陶瓷振动信号,以及2.5 MHz高频激光超声信号进行实验验证,结果表明:信号稳定且无纹波,系统分辨率为2.3 nm,信噪比提高16.7倍。两路干涉信号幅值分别为552 mV和736 mV,较传统外差干涉信号幅值提高近10倍,有利于纳米量级微振动信号的检测。 相似文献
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Based on the technique of dual-wavelength and principle of heterodyne interferometry, a modified method for measuring the
absolute distance is proposed. Because two test lights suffer from the same influence of wavelength drift in the measurement
setup, the minus effect coming from the wavelength drift can be offset. Therefore, the measurement accuracy can be significantly
increased. The feasibility of this method was demonstrated with a measurement resolution of about 1.50 μm. This method provides
the advantages of a simple optical setup, easy operation and rapid measurement. 相似文献
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采用相位法与极大值法测量超声波声速的准确度的研究 总被引:1,自引:0,他引:1
对极值法和相位法测量超声波声速的准确度问题进行了研究,实验与理论分析证明:相位法测量波长比极值法准确度要高.在与简谐运动有关的测量中,测量最大变化率点常常比测量最大值点的准确度要高,这在其他物理实验中也适用. 相似文献
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Non-contact method for measuring solution concentration using surface plasmon resonance apparatus and heterodyne interferometry 总被引:1,自引:0,他引:1
A simple non-contact method is proposed for measuring the concentration of solutions. Using the significant phase difference between p- and s-polarizations of the reflected light of a surface plasmon resonance apparatus, the variation in the phase difference, which is caused by a variation in the concentration of a test solution, can be accurately measured by common path heterodyne interferometry. Then, by substituting the corresponding variation in the incident angle of light at the base of the SPR prism in a specially derived equation, the concentration of the test solution can be determined. The validity of this method was demonstrated experimentally. This method is characterized by the advantages of the device having a simple non-contact structure; it being easy to operate; and its high accuracy, stability, and resolution. 相似文献
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爱因斯坦光电方程与光电效应实验外推法 总被引:9,自引:1,他引:9
讨论了爱因斯坦光电方程,指出现今在光电效应实验中普遍使用的爱因斯坦光电方程只是在T=0K时才成立。对室温下光电流的J-U曲线的分析表明,除T=0K情况外,光电子无明确的最大动能,也无明确的截止电压概念,改进了光电效应实验外推法,指出“截止电压”的确定必须在靠近零的同一光电流数值下进行,结果表明只有在以准爱因斯坦光电方程取代原有的爱因斯坦光电方程的情况下,光电效应外推法中内在的矛盾才可以消除。 相似文献
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This paper proposes an optical method for measuring small displacements using the surface plasmon resonance (SPR) heterodyne interferometry. A heterodyne light beam reflected by a mirror passes through a hemisphere glass and then enters into a surface plasmon resonance apparatus at the resonant angle. A small displacement of the mirror will introduce a phase-difference variation between p- and s-polarizations of the light emerging from the SPR apparatus. The phase-difference variation can be precisely measured with the heterodyne interferometric technique, and the associated displacement can be estimated. The feasibility of this method was verified by experiment, and the displacement measurement resolution of about 1.4 nm over a traveling range of 6 μm was achieved. Our method of measurement has the merits of both common-path interferometry and heterodyne interferometry. 相似文献
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A method of measuring micro-impulse with torsion pendulum based on multi-beam laser heterodyne
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In this paper, we propose a novel method of multi-beam laser heterodyne measurement for micro-impulse. The measurement of the micro-impulse, which is converted into the measurement of the small tuning angle of the torsion pendulum, is realized by considering the interaction between pulse laser and working medium. Based on Doppler effect and heterodyne technology, the information regarding the small tuning angle is loaded to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the oscillating mirror, thereby obtaining many values of the small tuning angle after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, the small tuning angle can be obtained accurately and the value of the micro-impulse can eventually be calculated. Using Polyvinylchlorid+2%C as a working medium, this novel method is used to simulate the value of the micro-impulse by MATLAB which is generated by considering the interaction between the pulse laser and the working medium, the obtained result shows that the relative error of this method is just 0.5%. 相似文献