Probing Human Vision with Orbital Angular Momentum of Light

前言：激光和光学技术在生物医学领域的应用非常频繁，特别是在眼睛健康方面。偏振光已经得到了广泛的研究，但在将波前图案操纵成螺旋结构以调查其在生物医学应用中的有效性方面，仍存在着严重的研究空白。具有轨道角动量(OAM)的偏振光可以具有更高的灵敏度和分辨率，使这种光特性优于传统使用的偏振光。特别是在眼睛健康方面，黄斑内混浊介质的散射特性还没有得到深入的研究。方法：该项目的主要目标包括研究和理解具有轨道角动量的偏振光，以及如何操纵它来达到其目的，以及确定眼部医学成像的最佳参数。将探索螺旋结构的微小变化对生物细胞的影响以及在灵敏度和分辨率方面的进步。数学模型：为了探索波前变化对表现不同螺旋大小的影响，代数公式将描述OAM变换，其分布在空间中，并且包括涉及时间尺度、脉冲宽度和时间重复率尺度的参数。因此，波前形状随时间的演变可以与空间和非均匀介质中脉冲的重复相结合，以复制生物物质中自然发生的传播方式。因此，可以探索光的OAM在生物相互作用环境中的行为影响。实验研究：将具有OAM特性的偏振光源安装在基于Mach-Zehnder的干涉仪中，研究其对类混浊散射介质的影响。为了推动这一方法，将使用模体的制造来演示这种偏振光对真实生物物质的影响。尺寸和性能应与人眼平行，并将通过CAD软件和3D打印设施进行制造，以验证上一步的理论数学模型。体模需要考虑的特性包括：预定义的手性双折射特性。散射特性。吸收特性。光的OAM诊断视网膜疾病的评估结合上述步骤的理论研究和实验研究的结果，偏振光与OAM的使用可以被评估其在生物医学方法中的应用，特别是在眼睛健康方面。可以对一种新的光学成像技术进行评估。该装置可用于组织的诊断和表征，具有最佳的灵敏度和分辨率。在研究了光的OAM对黄斑结构的影响后，可以对视网膜和黄斑进行筛查，以诊断DR和AMD，并可能对其进行治疗。意义：将光的OAM用于生物医学应用的探索将得到证实，以及用OAM确定黄斑内发现的类混浊散射介质特性及其对偏振光的响应。糖尿病视网膜病变和老年性黄斑变性都是严重影响患者生活质量的疾病，因此能够通过改变光学波前来有效诊断和治疗这些疾病的成像设备将对眼科领域产生巨大的影响。结论：在理论和物理模型的协作下，所进行的实验将展示OAM的偏振光的革命性发现，以及它如何诊断和治疗AMD和DR等视网膜疾病，这些疾病随后可以开发成具有高度特异性的新的光学成像设备。“

"Introduction: Lasers and optics have been applied in biomedical applications frequently and at great lengths particularly for ocular health. Polarised light has been researched extensively yet there is a profound research gap within manipulating the wavefront pattern into helical structures, to investigate their efficacy for biomedical applications. Polarised light with orbital angular momentum (OAM) can have greater sensitivity and resolution making this light property superior to conventionally used polarised light. Specifically in relation to ocular health, turbid-like media scattering properties located within the macular have not been investigated in depth.Method: The main objectives concerning the project includes the research and comprehension of polarised light with orbital angular momentum and how it can be manipulated for its purpose as well as determining the optimal parameters for ocular medical imaging. The small alterations in the helical structure effect on biological cells and the advancement in sensitivity and resolution will be explored. Mathematical Modelling: To explore the effect of alterations of wavefronts to manifest varying helical sizes, algebraic formulations will describe the OAM transformation which are distributed within space and including parameters involving time scales, pulse width and time repetition rate scales. Consequently, wavefront shape evolution against time can be depicted coupled with space and repetition of pulses within inhomogeneous media to replicate how the propagation would naturally occur in biological matter. Thus, the behavioural influence of OAM of light within a biological interaction context can be explored. Experimental studies: Using a polarised light source with OAM characteristics will be installed within a Mach-Zehnder based interferometer to study its effect on turbid-like scattering media. To propel this method, the fabrication of a phantom will be used to demonstrate the effects such polarised light will have on real biological matter. The size and properties shall run parallel to the human eye and will be fabricated via a CAD software and 3D printing facility to validate the theoretical mathematical model from the previous step. The properties to consider for the phantom are: Predefined chiral Birefringence properties. Scattering properties. Absorption properties. Evaluation of OAM of light for diagnosis of retinal diseases Coupling the results of theoretical studies and experimental studies of the steps mentioned, the usage of polarised light with OAM can be evaluated for its application in biomedical approaches, particularly for ocular health. An assessment for a new optical imagining technique can be addressed. The device can be used in diagnosis and characterisation of tissues with optimal sensitivity and resolution. The retina and macular can be screened to diagnose DR and AMD and perhaps treat them also, after investigating the structural impact on the macular due to OAM of light. Significance: The exploration of using OAM of light in biomedical applications will be substantiated as well as the determination of turbid-like scattering media properties found within the macular and its response to polarised light with OAM. DR and AMD are diseases which drastically effect quality of life and thus an imaging device which can effectively diagnose and treat these diseases via alteration of the optical wavefronts will impact the ophthalmology field tremendously. Conclusion: With the collaboration of theoretical and physical models, the experimentations conducted will demonstrate the revolutionary findings of polarised light with OAM and how it may diagnose and treat retinal diseases such as AMD and DR, which can subsequently be developed into a new optical imaging device with great specificity. "