自加速光场和阵列光场的研究及在光捕获中的应用

发布时间：2017-12-30 19:36

本文关键词：自加速光场和阵列光场的研究及在光捕获中的应用　出处：《中国科学技术大学》2016年博士论文　论文类型：学位论文

【摘要】：光镊是基于光的力学效应捕获和操控微观粒子的工具。光镊最早由Ashkin发明,它通过会聚高斯光形成的三维光势阱来实现微粒捕获。光镊的作用力和作用尺度分别为皮牛和微纳量级,这使得它在软物质,分散体系和单分子等领域研究中具有广泛应用。然而随着新兴领域的发展和对光镊操控新要求的提出,传统高斯光镊也面临着诸多应用困境,如对系宗微粒的同时操控或者选择性捕获,异质体粘弹性测量,低折射率或吸热粒子三维捕获以及生物组织内的深度捕获等。这些问题的解决有赖于发展新型光镊捕获技术,同时对推动软物质和生物物理等领域的研究进展也具有重要意义。自加速光场和阵列光场是目前衍射光学领域的研究热门,通过在光镊系统中引入这些新型光场有望解决传统高斯光的捕获困境。自加速光场是新近研究的一个热点,它是一类光场的总称,典型代表有艾利光和圆对称艾利光等,它们一般都是波动方程的解,都能通过衍射光学元件实验生成。相较会聚高斯光,自加速光场具有特殊的光场结构和传输轨迹,因此应用在光捕获领域有望捕获特殊粒子或开发出新的光捕获形式。阵列光场的典型代表是阵列高斯光,一般通过空间光调制器对高斯光相位调制生成,目前人们已经建立了完善的阵列高斯光生成算法。阵列高斯光阱的特点是能对不同体系的多微粒进行同时捕获和操控,它有望解决软物质领域中的自组装和异质体粘弹性测量等问题。本人博士阶段工作主要集中在自加速光场和阵列光场的特性研究以及发展它们在光镊捕获和软物质粘弹性测量等领域的应用。本文主要有以下几部分内容:1.综述了自加速光场和阵列光场的理论基础和发展现状,以及液晶空间光调制器的复振幅调制技术。2.基于角谱理论,提出了两种振幅模板并研究了它们对对称艾利光的振幅调制。第一种为指数振幅模板,它能在角谱面上抑制对称艾利光的相关频谱分量,据此我们得到了一种新的补偿加速光场。这种加速光场能在不同损耗介质保持主瓣光强传输不变,还兼有衰减震荡传输特性,具有这些性质的自加速光场是我们首次报道的,它有望应用于损耗介质(如生物组织)的深度光操控中。第二种为对称振幅模板,我们理论和实验研究了这种振幅模板对对称艾利光的振幅调制,发现它能增强光场的高频频谱分量,进而提高对称艾利光的自聚焦特性和轴向梯度力,这种新型振幅调制的对称艾利光能提高光镊对系宗微粒的捕获稳定性。3.通过对称化三阶多边形光场角谱,提出了一种新的对称多边形加速光场。理论和实验研究了这种加速光场的传输特性,发现该光场除具有自聚焦特性外,还有针形中心光瓣和对称多通道旁瓣的光场结构,实验也发现它具有强自修复特性。进一步的,我们将该光场耦合进光镊系统,实现了这种对称加速光场能对不同空间位置微粒的选择性输运和捕获,这种多通道结构的自加速光场有望在光流体等领域得到重要应用。4.利用一种新的可调控光瓶实现了对水溶液中吸热粒子的可调控捕获。光瓶由修正贝塞尔函数叠加生成,通过改变几何参量能调控光瓶的暗区大小和暗度。实验基于液晶空间光调制器的复振幅调制技术来实验生成光瓶并用于光捕获。我们分析了不同暗区暗度的光瓶对吸热粒子的光泳力影响,并通过调节几何参量大小,实现了不同暗度光瓶对吸热粒子的可调控捕获。光瓶光场能解决光镊对特殊粒子如吸热粒子的捕获问题。5.搭建了消像差的阵列高斯光镊装置,实现了阵列高斯光阱对软物质粘弹性的多微区并行测量。实验首先利用相位补偿技术对阵列高斯光镊光路进行了像差校正,实验使得阵列光阱刚度提高了 40%。基于前期像差校正工作,我们改进了阵列高斯光镊光路。同时通过GS算法生成了高质量阵列多光阱并用于测量软物质的多微区粘弹性。实验结果说明了阵列多光阱的并行测量能提高实验精度,同时也验证了它的多微区测量能力,我们工作为后续利用阵列多光阱测量异质体粘弹性打下了良好基础。基于以上工作,我们建立了新型光场光镊捕获和应用的一些计算和实验研究方法。并从传统高斯光镊的应用困境出发,分别对自加速光场和阵列光场的传输特性进行了较为深入研究和进一步优化,提出了一些新的自加速光场并演示了它们在光捕获中的应用。我们相信这些工作对光镊在软物质,生物医学等领域的研究具有一定借鉴意义。
[Abstract]:Optical tweezers is the mechanical effect of light trapping and manipulation of micro particles in optical tweezers based tools. The earliest invented by Ashkin, it is by the convergence of three dimensional optical trap Gauss light form to realize particle capture. Forces and scale of optical tweezers were cattle skin and micro nano, which makes it in soft matter, has application study on dispersion system and single molecular fields. However, with the development of the emerging field of control and new requirements for optical tweezers is proposed, the traditional Gauss optical tweezers is also faced with many difficulties in the application of the system, such as in particle manipulation or selective capture at the same time, measuring different plastid viscoelasticity, low refractive index or endothermic three-dimensional particle capture and capture the depth of biological tissue. The solution of these problems depends on the development of new optical tweezers technology, but also has important significance to promote the progress of soft matter and biological physics and other fields. Since the The speed of light field and array light field is currently hot research field of optical diffraction, through the introduction of these new light in the optical tweezers system is expected to solve the plight of traditional Gauss light capture. Self accelerating light field is a research hotspot recently, it is a general term for a class of light field, a typical representative of Ai Liguang and circular symmetry avery light, they are generally the solution of wave equation can be experimentally generated diffractive optical elements. Compared with the convergence of Gauss light, self accelerating light field with special optical field structure and transmission path, so the application in light harvesting areas is expected to capture special particles or develop new light capture typical array form. The light field is an array of Gauss light, generally through the spatial light modulator of Gauss optical phase modulation generation, at present people have established a perfect array generation algorithm for optical Gauss. Gauss is the characteristics of the array optical trap to different systems The particles are also captured and manipulated, it is expected to solve the self-assembly and heterogeneous viscoelastic measurement problems in the field of soft matter. My doctoral work focused on the self accelerating phase of the light field and array light field characteristics of research and development and their applications in optical tweezers and soft material viscoelasticity measurement and other fields. This paper consists of the following parts: 1. the paper summarizes the basic theory and development status of accelerated light field and array light field, and liquid crystal spatial light modulator.2. complex amplitude modulation technique based on angular spectrum theory, put forward two kinds of amplitude mask and to study their avery of symmetrical light amplitude modulation. The first one is the index the amplitude of the template, the relevant spectral components it can suppress the symmetric avery light in the angular spectrum of plane, so we can get a new compensation accelerated light field. This acceleration field can keep the main loss in different medium Light transmission valve also has the shock attenuation constant, the transmission characteristics of these properties, self accelerating field is reported for the first time, it is expected to be applied to the medium loss (such as biological tissue). The depth of the optical manipulation of second kinds of symmetric amplitude template, our theoretical and experimental research of the amplitude modulation of the amplitude of the symmetric template avery light, it can enhance the high-frequency spectral components of the light field, and improve the self focusing characteristics and axial gradient force symmetry avery light, avery light symmetric amplitude modulation of this new type of optical tweezers system to improve the stability of.3. in particle capture by symmetric three order polygon light field angular spectrum, proposes a new the symmetrical polygon acceleration field. The transmission characteristics of optical field accelerate the theoretical and experimental research, found that the light field has self focusing properties, and needle valve and multi channel optical center symmetric sidelobe light Field structure, experiments have found that it has strong self repairing characteristics. Further, we will be the light coupled into the optical tweezers system, realized the symmetric light field can accelerate the selectivity of different spatial position of particle transport and capture, self accelerating light field is expected to be a new adjustable light bottle for endothermic particles in aqueous solution can be used to capture the important application of.4. control in the field of optical fluid of the multi-channel structure. The light bottle produced by the modified Bessel function superposition, by changing the geometric parameters can control the light bottle dark area size and dark. The complex amplitude modulation technology based on liquid crystal spatial light modulator to generate optical experiment the bottle and used to capture light. We analyzed the photophoretic force light dark dark bottles of different degree of heat absorbing particle effects, and by adjusting the geometric parameters of size, to achieve a different light dark bottle of particles can be controlled to capture heat Light. Light field optical tweezers can solve the bottle of special particles such as heat absorbing particle acquisition problem of.5. to build the Gauss array optical tweezers device of optical aberration, the array of optical trap Gauss soft material viscoelastic multi micro parallel measurement. Experiment first array optical tweezers were Gauss optical aberration correction by using phase compensation technology experiment makes the array of optical trap stiffness improves the pre 40%. aberration correction based on the work, we improved the optical tweezers array of Gauss road. At the same time through the GS algorithm to generate high quality array optical tweezers and used to measure the soft material multi micro area viscoelastic. Experimental results prove that the parallel measurement can improve the precision of array multiple optical tweezers, and validate its multi micro measurement capability, our work lays a good foundation for the subsequent use of array of optical trap measuring heterogeneous viscoelastic. Based on the above work, we have established a new light field Optical tweezers and application of some computational and experimental research method. And from the point of view of the difficulties in the application of traditional Gauss optical tweezers, respectively on the self accelerating light field and array light field transmission characteristics are studied deeply and further optimization, and puts forward some new self accelerating light field and demonstrates their application in optical capture. We believe that these work of optical tweezers in soft matter, has certain reference significance in biomedical research and other fields.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O439

【相似文献】