Polarization Modulation Of Light Field And Its Application In Optical Imaging

With the development of modern optical technology,people are increasingly aware that light can not only carry rich information but also serve as a means of exploring the material world.Therefore,light has a prominent advantage as a carrier of information^and the regulation of the light field is also more important.Phase and amplitude are the two basic control parameters of the light field,and their corresponding control techniques and methods have been perfected.The polarization state is another regulation parameter of light field regulation,and its regulation technology needs to be improved and developed.Therefore,the method of polarization as the light field regulation has been widely concerned by experimenters.This thesis focuses on the polarization modulated light field and its application in optical imaging.The thesis analyzes the characteristics of the new vector beam,the perfect Poincare beam.The thesis studies the relationship between the polarization state of the perfect Poincare beam and the phase of the computed hologram that produced this beam.At the same time,this thesis designs a convenient and universally applicable experimental scheme to generate the bearm,and verifies the feasibility of the scheme.It proves that the beam can be realized without changing the optical path system.It implements the conversion between the basic Poincare sphere,the high-order Poincare sphere and the hybrid Poincare sphere,which is important for producing a structured perfect Poincare beam.The thesis designs a new method for generating and modulating an elliptic perfect vector beam(EPVB)and elliptic perfect optical vortex(EPOV)beam base on the dynamic and geometric phases.The thesis theoretically analyzes the modulation basis of geometric phase and dynamic phase.The geometric phase can be adjusted according to the polarization state,and the phase vortex to vector polarization can be converted by changing the polarization state of the incident light.The shape of the beam can be changed from circle to ellipse by setting the scale factor m of the dynamic phase.We verified the scheme through experiments,and the experimental results are consistent with the theoretical analysis.The geometric phase modulation proposed by this scheme provides additional freedom to manipulate the phase and polarization of the light field,and the combination of geometric phase and dynamic phase provides a convenient and flexible way to integrate optical and fiber applications.The thesis designs a scheme based on polarization modulation to achieve scalar vortex filtering and vector vortex filtering.In vector and scalar vortex filtering,we theoretically analyze the cause of the shadow effect of the vector optical element Q-plate in the case of the center off-axis.At the same time,we compared the difference between the autofocus Airy beam and the Gaussian beam as the illumination source.The results show that higher eontrast and lower noise can be achieved with autofocus Airy beam illumination.