Study Of Optical Materials And Devices Based On Magneto-optical Surface Plasmon Polariton

Magnetoplasmon is the interdiscipline researched on interaction between surface plasmon resonance and magneto-optical materials.Through combined magnetic materials with SPR structure,some new optical phenomenon can be achieved,such as magnetic field control SPR wave vector,SPR enhance magneto-optical effects.The materials and devices based on magnetoplasmonic phenomenon show significant applications in biosensing and magnetic field sensing area.Conventional mangnetoplasmonic systems are based on pure ferromagnetic metals,such as Fe,Co and Ni,and noble metal/ferromagnetic metals multilayer structures.However,the magnetoplasmonic structure based on pure metallic materials can only support surface plasmon mode,which limit the structure of devices and tunable mechanism of the mode.In another side,the high optical loss of ferromagnetic metals limits the improvement of the sensing performance.These problems have been the bottleneck restriction of magnetoplasmonic development.Based on the above background,we propose to use transparent magnetic oxides?yttrium iron garnet,YIG and doped YIG?instead of ferromagnetic metals to establish a series of new magentoplasmonic structures.In physics,we achieve the innovations of the electromagnetic tunable mechanism using waveguide mode and cavity mode.To achieve strong electromagnetic nonreciprocity based on relevant structure,we develop the magneto-optical nonreciprocal metasurfaces devices.In applications,we significantly improve the sensitivity of devices,and achieve high figure of merit in biosensing.The detailed research contents have following aspect:1.According to the low loss of Ag and high magneto-optical effect of Ce:YIG at wavelength around 1000 nm,we design the Ag/Ce:YIG structure.We can achieve the enhancement of transverse magneto-optical Kerr effect of the Ce:YIG film through exciting of surface plasmon mode at interface between Ag and Ce:YIG.Finally,we achieve a high sensitive index sensor with optimizing the structure.2.We design the TiN/?SiO₂/YIG/Ce:YIG?/Au metal-insulator-metal structure.Through the coupling between waveguide mode in magneto-optical dielectric layer and surface plasmon mode at interface of Au/air,we achieve a high Q asymmetric Fano line shape.After that,we obtain an ultrahigh figure of merit index sensor by taking the transverse magneto-optical Kerr effect as sensing signal.Finally,we experimentally fabricate the sample and demonstrate the application for the biosensor.The limit-of-detection show 16?higher compared to a standard Au SPR sensor.3.We design the TiN/?SiO₂/YIG/Ce:YIG?/Au nanohole structure.The magneto-optical effect of the magnetic oxides is significantly enhanced by the localized plasmon resonance in the hole structure.Based on the mode,we use the magnetic field to control the extrinsic chirality of the hole structure,and firstly obtain the switching of the chirality using magnetic field in near infrared wavelength,which has an order improvement compared to the state-of-art results.4.We expand the magnetoplasmonic structure to THz frequency and design the Au grating/graphene/high resistance silicon structure.Through the coupling between surface plasmon resonance of the grating and waveguide mode in silicon,we achieve simultaneously enhancement of transmission and magneto-optical Faraday effect.Moreover,we can achieve the both enhancement at the whole THz frequency range,through the device size design,which has potential application of THz Faraday rotator.5.We propose the all dielectric nonreciprocal metasurfaces based on magneto-optical effect to completely instead of high loss metallic materials in magnetoplasmonic structure.Achieving the one-way transmission of electromagnetic wave and nonreciprocal phase controllable based on all dielectric resonance.Achieving the nonreciprocal modulation of all the far field characteristic based on generalized Snell law,termed as‘generalized electromagnetic nonreciprocity'.In experiment,we choose the high coercivity and saturation magnetization Ba ferrite material working at microwave frequency and successfully fabricate the self-biased magneto-optical nonreciprocal metasurfaces.The experimental results confirm the validity of the theoretical results.And we solve the challenge of the requirement for bulk magnet.