The Manipulation And Applications Of Bloch Surface Wave

The Bloch surface wave(BSW)is one kind of surface electromagnetic modes confined at the interface between a dielectric multilayer and a semi-infinite uniform medium,and can be regarded as a dielectric version of low-loss surface plasmon polaritions(SPPs).Similar to SPPs,by changing the surface morphology and material properties of the propagation interface,different structures can be designed to effectively modulate the optical field of BSW so that the generation,transmission,manipulation,transformation and the principle of interaction with matter of photon can be studied at nanometer scale and display various novel optical phenomena.The new micro-nano optical functional devices such as optical manipulation multi-dimensional light fields control,super-resolution imaging,large viewing angle holography,and highly integrated on-chip spectral detection,photonic routing based on BSW can be realized.Based on the comparison between BSW and SPPs,this paper realizes the excitation and shaping of BSW and obtains optical devices such as the surface optical waveguide,reflectors,beam splitters,polarization converters,and optical switches based on BSW by analyzing and characterizing dielectric multilayers and surface micro-nanocomposite structure by means of theory and experimental methods.Research on these issues not only has extremely important theoretical value,but also promotes the application of optics in the fields of information,chemistry,life and materials.The main research of this work as follows:(1)The physical mechanism and definition of the light field on Bloch surface wave are analyzed in depth by using the photonic bandgap theory.By carefully designing structure of the dielectric multilayers and compounding it with a single polymer nanofiber,we proposed and implemented a novel one-dimensional Bloch surface mode and compared the dielectric-loaded Bloch surface wave(DLBSW)with one-dimensional Bloch surface wave(1D-BSW)mode in theory.It demenstrate that the one-dimensional BSW mode has better local and sensing performances.In the experiment,plasma enhanced chemical vapor deposition was used to prepare the dielectric multilayers and polymer nanofibers were prepared by electrospinning.The laser and fluorescence of one-dimensional BSW can be transmitted in polymer nanofibers and we can obtain the results by using a self-built leaky radiation microscope system.We can also realizes the transition of DLBSW to 1DBSW with different wavelengths on a multilayer dielectric substrate and the simultaneous excitation of fluorescence signal of Bloch surface wave with different wavelengths by modifying chemical composition of the polymer nanofibers.(2)A pair of cross-coupled gratings on the dielectric multilayer was used to transform a free-space 3D Gaussian beam into two-dimensional BSWs(2D-BSWs).Based on this structure we proposed and implemented the diffraction-free BSW in the liquid medium environment.The back-focal-plane imaging technique is used to verify that the diffraction-free BSW is obtained by the interference of two planar 2D-BSWs generated by the cross-gratings.The diffraction-free BSW does not diffract after passing through three particles or larger-sized microfiber structures.The parameters of the dielectric multilayers were adjusted to abtain the diffraction-free BSW in the air environment.(3)The composite structure of dielectric multilayers and single silver nanowires was experimentally studied.Instead of focused ion beam or electron beam lithography,we used the silver nanowires which are easily to synthesize and manipulate as the far-near field couplers and the excitation,propagation of BSW was realized.The use of curved silver nanowire structure can focus the 2D-BSW.Further,the shapped three-dimensional structured light field obtained by the spatial light modulator is converted into 2D-BSW structured light field,thereby realizing dynamic regulation of the propagation direction,width,and transmission length of 2D-BSW.(4)The dielectric multilayers with both polarization in transverse electric and transverse magnetic 2D-BSW modes are designed.The effects of the width and depth of the one-dimensional slit structure on the dielectric multilayers on the reflection,transmission,and mode conversion coefficients of the 2D-BSW incident on it were studied.The relationship between reflectance,transmission,mode conversion coefficient and incident angle of the BSW after passing through the slit were studied by the finite-difference time-domain method and rigorous coupled-wave analysis.Based on the theoretical research results,a 2D-BSW emitter,reflector,polarization converter,optical single pole double throw switch and other two-dimensional integrated optics were obtained by reasonably etching the slit structure on the dielectric multilayers in the experiment.(5)A metal-dielectric composite multilayer,namely plasma coupled waveguide structure is proposed.Similar to the dielectric multilayers,two polarization modes can be supported.By using the transfer matrix method,the structural parameters are rationally designed to obtain the desired modes and their field distribution.In the experiment,two modes are excited at the same time,and the fields of the two modes are respecively used to excite the corresponding position fluorescence.At the same time,the two types of polarization modes can be selectively excited by using an electrodynamic liquid crystal and a polarizer,thereby controlling the selective excitation of fluorescence signals on the surface and in the bulk of the sample.The innovations of this paper mainly include:(1)The new physical concept of one-dimensional Bloch surface wave mode was proposed.The dielectric multilayers was composited with polymer nanofibers to solve the technical problem that that the ultrafine polymer nanofibers could not transmit light on ordinary glass substrates.Polymeric nanofibers were chemically modified to achieve simultaneous excitation of fluorescence signals at different wavelengths.(2)The diffraction-free BSW sustained on the dielectric multilayer in the liquid or air environment is proposed and implemented.The back-focal-plane technique is used to prove the principle of diffraction-free BSW,and it is further verified that the diffraction-free BSW can pass through multiple obstacles.(3)A single silver nanowire was used to realize the excitation,transmission and focusing of BSW in liquid phase environment.By using the spatial light modulator to modulate the phase information of the excitation light field,we obtained the reconfigurable 2D-BSW for the first time.(4)The 2D-BSW was manipulated and implemented by using one-dimensional slits.The phenomenons of total reflection,beam splitting,and mode conversion of the two-dimensional bloch surface wave were studied.For the first time,the TE and TM BSW modes were converted to each other and abnormal reflection phenomena with different reflection angles were observed.