陣列共焦系統(tǒng)中空間光調(diào)制方法研究
發(fā)布時間：2018-11-07 21:44
【摘要】：陣列共焦顯微技術(shù)以其高效并行的掃描能力,成為生物醫(yī)學、微結(jié)構(gòu)加工等快速在線三維檢測中的研究熱點。然而,由于微結(jié)構(gòu)光學元件加工的限制,為避免產(chǎn)生耦合疊加效應(yīng),微透鏡陣列的間隔一般在100μm左右;此外,由于微透鏡的數(shù)值孔徑較小,其聚焦特性較低,嚴重降低了軸向探測能力。近年來,空間光調(diào)制器可在不改變光學系統(tǒng)結(jié)構(gòu)的情況下,對光束進行相位和幅值調(diào)制,大大增加了系統(tǒng)設(shè)計的靈活性。本課題利用空間光調(diào)制器對陣列共焦系統(tǒng)的光束進行調(diào)制,以實現(xiàn)高效率快速掃描;同時利用其替代光瞳濾波器,實現(xiàn)對探測空間聚焦場的調(diào)制。本課題“陣列共焦系統(tǒng)中空間光調(diào)制方法研究”的主要完成的工作如下:(1)建立了無限遠共軛距共焦成像系統(tǒng)的數(shù)學模型,理論分析了在無限距共焦系統(tǒng)中陣列共焦成像系統(tǒng)的原理,以及收集物鏡的數(shù)值孔徑對系統(tǒng)軸向分辨力的影響。(2)設(shè)計了閃耀光柵的結(jié)構(gòu),通過改變其結(jié)構(gòu)參數(shù)控制光束偏轉(zhuǎn),加入陣列式共焦顯微成像系統(tǒng),使其能夠在較大視場范圍內(nèi)完成高密集橫向掃描,進一步提高陣列共焦系統(tǒng)并行掃描效率。(3)設(shè)計了相位光瞳濾波器的結(jié)構(gòu),將液晶空間光調(diào)制器放置在共焦系統(tǒng)探測臂中模擬相位光瞳濾波器,在不改變針孔位置的情況下,實現(xiàn)離焦探測,進而利用差分方法實現(xiàn)陣列共焦系統(tǒng)軸向分辨力的提高。(4)分析液晶空間光調(diào)制器相位調(diào)制特性影響因素,提出利用泰曼-格林干涉方法測定液晶空間光調(diào)制器的相位調(diào)制特性,并利用傅里葉變換的方法對采集圖像進行處理。最后搭建相關(guān)實驗平臺,實驗結(jié)果表明:液晶空間光調(diào)制器的相位調(diào)制量達到2?,相位調(diào)制量的PV值小于0.04rad,標準差小于0.011rad。對閃耀光柵偏轉(zhuǎn)角進行測量,其光斑位置的漂移對偏轉(zhuǎn)角的影響小于0.028mrad,測量值與理論值的誤差小于2%。與微透鏡陣列相結(jié)合,聚焦光斑陣列最大掃描范圍為19.88μm,最小掃描間隔為4.63μm,對應(yīng)光束偏轉(zhuǎn)的最大角度為14.5mrad,最小角度為3.4mrad。利用液晶空間光調(diào)制器模擬相位光瞳濾波器實現(xiàn)了移焦效應(yīng),能夠?qū)崿F(xiàn)差動共焦顯微探測,并且軸向分辨力提高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%.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN761
本文編號：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%.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN761
【參考文獻】
相關(guān)期刊論文 前2條
1 陳懷新,隋展,陳禎培,陳仁元,李明中;液晶電視LCTV的光學調(diào)制特性及其應(yīng)用[J];中國激光;2000年08期
2 張彩;黃永梅;亓波;邊疆;吳瓊雁;;基于液晶空間光調(diào)制器的光束偏轉(zhuǎn)控制[J];中國激光;2011年09期
相關(guān)碩士學位論文 前1條
1 尹可;基于微透鏡陣列的多光束共焦成像系統(tǒng)若干問題的研究[D];哈爾濱工業(yè)大學;2013年
，本文編號：2317651
本文鏈接：http://sikaile.net/kejilunwen/dianzigongchenglunwen/2317651.html
最近更新
教材專著
