Light Field Manipulation And Holography Based On Surface Plasmon Polaritons

Mirco-and nano-photonics is an important research area of optics in the past decade.It focuses on the propagation and interaction of light at wavelength and sub-wavelength scales.This research is crucial to the development of miniaturization and integration of optical devices.In recent years,in plasmonics and metamaterial,many novel results have been achieved in the area of optical sensing and detection,optical imaging,and optical information transmission.As a representative,metalens has been thoroughly studied from theory to actual device products.This thesis focuses on the research of several kind of light field manipulation,imaging and detection from the perspective of spatial light field and surface light field conversion.The content is constructed as follows:1.We developed the holographic method in beam manipulation and successfully realized an oscillating plasmonic beam.In this method the plasmonic beam is regarded as an object composed of a series of image points which possess certain phase distribution.In the experiment,the amplitude is manipulated by the number of scatterers in the horizontal direction,and the phase is controlled by the relative position.The object light and the reference light are both surface waves,which greatly reduces the space of the imaging system,and conforms to the trend of integration and miniaturization of optoelectronic devices.2.The multiplexed hologram is realized with a surface plasmon wave as the reference light and a spatial wave as the object wave.First is to use different propagating surface plasmon waves,we realized a four-fold multiplexed hologram.This method can theoretically realize up to 18 channels for multiplexing with nearly no crosstalk.Then a multiplexed hologram combining propagation and polarizations is designed.By rotating the polarizers,another four-fold multiplexed hologram with higher image quality can be realized.We also extended the design,using guided modes in the dielectric-loaded waveguide as reference waves,and successfully realized the multiplexing of TEO and TMO mode as well as TE0 and TE1 modes in the waveguide.The proposed holographic design with a surface-to-space radiation conversion provides new ideas for the design of augmented reality(AR)and virtual reality(VR)devices.3.A method for detecting the modes of spatial orbital angular momentum beam is proposed,by coupling it into a split surface plasmon signal.By the wave vector analysis,the relation between the modes and the signal is obtained.Since the method require no alignment,it can helps to the robustness and accuracy of the detection device.In addition,we propose a combined grating with two periodics.It is found that the orbital angular momentum beam can be coupled into different direction which is determined by the sign of the topologcial charge.Therefore,the design can achieve a complete detection of the orbital angular momentum modes.4.We did an initial research on two topics,one is the three-dimensional light field imaging and the other is imaging through scattering medium by machine learning algorithm.We experimentally used metalens array to achieve the light field acquisition and refocus imaging at different positions.In addition,we have made a preliminary attempt to image through scattering media using a deep learning algorithm.Machine learning,including deep learning,when is applied to the field of optics,can play an important role in complex systems.