阵列共焦系统中空间光调制方法研究
发布时间：2018-11-07 21:44
【摘要】：阵列共焦显微技术以其高效并行的扫描能力,成为生物医学、微结构加工等快速在线三维检测中的研究热点。然而,由于微结构光学元件加工的限制,为避免产生耦合叠加效应,微透镜阵列的间隔一般在100μm左右;此外,由于微透镜的数值孔径较小,其聚焦特性较低,严重降低了轴向探测能力。近年来,空间光调制器可在不改变光学系统结构的情况下,对光束进行相位和幅值调制,大大增加了系统设计的灵活性。本课题利用空间光调制器对阵列共焦系统的光束进行调制,以实现高效率快速扫描;同时利用其替代光瞳滤波器,实现对探测空间聚焦场的调制。本课题“阵列共焦系统中空间光调制方法研究”的主要完成的工作如下:(1)建立了无限远共轭距共焦成像系统的数学模型,理论分析了在无限距共焦系统中阵列共焦成像系统的原理,以及收集物镜的数值孔径对系统轴向分辨力的影响。(2)设计了闪耀光栅的结构,通过改变其结构参数控制光束偏转,加入阵列式共焦显微成像系统,使其能够在较大视场范围内完成高密集横向扫描,进一步提高阵列共焦系统并行扫描效率。(3)设计了相位光瞳滤波器的结构,将液晶空间光调制器放置在共焦系统探测臂中模拟相位光瞳滤波器,在不改变针孔位置的情况下,实现离焦探测,进而利用差分方法实现阵列共焦系统轴向分辨力的提高。(4)分析液晶空间光调制器相位调制特性影响因素,提出利用泰曼-格林干涉方法测定液晶空间光调制器的相位调制特性,并利用傅里叶变换的方法对采集图像进行处理。最后搭建相关实验平台,实验结果表明:液晶空间光调制器的相位调制量达到2?,相位调制量的PV值小于0.04rad,标准差小于0.011rad。对闪耀光栅偏转角进行测量,其光斑位置的漂移对偏转角的影响小于0.028mrad,测量值与理论值的误差小于2%。与微透镜阵列相结合,聚焦光斑阵列最大扫描范围为19.88μm,最小扫描间隔为4.63μm,对应光束偏转的最大角度为14.5mrad,最小角度为3.4mrad。利用液晶空间光调制器模拟相位光瞳滤波器实现了移焦效应,能够实现差动共焦显微探测,并且轴向分辨力提高80%。
[Abstract]:Array confocal microscopy (ACM), with its high efficiency and parallel scanning ability, has become a research hotspot in biomedicine, microstructural processing and so on. However, in order to avoid the coupling superposition effect, the interval of microlens array is generally about 100 渭 m due to the limitation of fabrication of microstructural optical elements. In addition, because the numerical aperture of microlens is small, its focusing characteristic is low, which seriously reduces the axial detection ability. In recent years, the spatial light modulator can modulate the phase and amplitude of the beam without changing the structure of the optical system, which greatly increases the flexibility of the system design. In this paper, the spatial light modulator is used to modulate the beam of the array confocal system in order to realize the high efficiency and fast scanning. At the same time, instead of the pupil filter, the modulation of the detecting space focusing field is realized. The main work of this thesis is as follows: (1) the mathematical model of an infinite conjugate range confocal imaging system is established. The principle of the array confocal imaging system in an infinite range confocal system is theoretically analyzed, and the influence of the numerical aperture of the objective lens on the axial resolution of the system is analyzed. (2) the structure of the blazed grating is designed. By changing the structure parameters to control the beam deflection and adding the array confocal microscopic imaging system, it can complete high density transverse scanning in a large field of view. The parallel scanning efficiency of the array confocal system is further improved. (3) the phase pupil filter is designed and the liquid crystal spatial light modulator is placed in the detecting arm of the confocal system to simulate the phase pupil filter. Without changing the pinhole position, defocus detection is realized, and then the axial resolution of the array confocal system is improved by differential method. (4) the factors affecting the phase modulation characteristics of liquid crystal spatial light modulator are analyzed. The phase modulation characteristics of liquid crystal spatial light modulator are measured by using Tymann-Green interferometry, and the image acquisition is processed by Fourier transform. The experimental results show that the phase modulation of the liquid crystal spatial light modulator is up to 2g, the PV of the phase modulation is less than 0.04rad, and the standard deviation is less than 0.011rad. The deflection angle of the blazed grating is measured. The effect of spot position on the deflection angle is less than 0.028 mrad.The error between the measured value and the theoretical value is less than 2. Combined with microlens array, the maximum scanning range of focused spot array is 19.88 渭 m, the minimum scanning interval is 4.63 渭 m, the maximum angle of beam deflection is 14.5mradand the minimum angle is 3.4 mrad. Using liquid crystal spatial light modulator to simulate the phase pupil filter, the focusing effect is realized, the differential confocal microscopy detection can be realized, and the axial resolution is increased by 80%.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN761
本文编号：2317651
[Abstract]:Array confocal microscopy (ACM), with its high efficiency and parallel scanning ability, has become a research hotspot in biomedicine, microstructural processing and so on. However, in order to avoid the coupling superposition effect, the interval of microlens array is generally about 100 渭 m due to the limitation of fabrication of microstructural optical elements. In addition, because the numerical aperture of microlens is small, its focusing characteristic is low, which seriously reduces the axial detection ability. In recent years, the spatial light modulator can modulate the phase and amplitude of the beam without changing the structure of the optical system, which greatly increases the flexibility of the system design. In this paper, the spatial light modulator is used to modulate the beam of the array confocal system in order to realize the high efficiency and fast scanning. At the same time, instead of the pupil filter, the modulation of the detecting space focusing field is realized. The main work of this thesis is as follows: (1) the mathematical model of an infinite conjugate range confocal imaging system is established. The principle of the array confocal imaging system in an infinite range confocal system is theoretically analyzed, and the influence of the numerical aperture of the objective lens on the axial resolution of the system is analyzed. (2) the structure of the blazed grating is designed. By changing the structure parameters to control the beam deflection and adding the array confocal microscopic imaging system, it can complete high density transverse scanning in a large field of view. The parallel scanning efficiency of the array confocal system is further improved. (3) the phase pupil filter is designed and the liquid crystal spatial light modulator is placed in the detecting arm of the confocal system to simulate the phase pupil filter. Without changing the pinhole position, defocus detection is realized, and then the axial resolution of the array confocal system is improved by differential method. (4) the factors affecting the phase modulation characteristics of liquid crystal spatial light modulator are analyzed. The phase modulation characteristics of liquid crystal spatial light modulator are measured by using Tymann-Green interferometry, and the image acquisition is processed by Fourier transform. The experimental results show that the phase modulation of the liquid crystal spatial light modulator is up to 2g, the PV of the phase modulation is less than 0.04rad, and the standard deviation is less than 0.011rad. The deflection angle of the blazed grating is measured. The effect of spot position on the deflection angle is less than 0.028 mrad.The error between the measured value and the theoretical value is less than 2. Combined with microlens array, the maximum scanning range of focused spot array is 19.88 渭 m, the minimum scanning interval is 4.63 渭 m, the maximum angle of beam deflection is 14.5mradand the minimum angle is 3.4 mrad. Using liquid crystal spatial light modulator to simulate the phase pupil filter, the focusing effect is realized, the differential confocal microscopy detection can be realized, and the axial resolution is increased by 80%.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN761
【参考文献】
相关期刊论文 前2条
1 陈怀新,隋展,陈祯培,陈仁元,李明中;液晶电视LCTV的光学调制特性及其应用[J];中国激光;2000年08期
2 张彩;黄永梅;亓波;边疆;吴琼雁;;基于液晶空间光调制器的光束偏转控制[J];中国激光;2011年09期
相关硕士学位论文 前1条
1 尹可;基于微透镜阵列的多光束共焦成像系统若干问题的研究[D];哈尔滨工业大学;2013年
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