Probing Human Vision with Orbital Angular Momentum of Light

点击翻译按钮获取中文摘要

"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. "