Study On Lightwave Reflection And Transmission Properties Of Metallic Micro-nano Arrays Controlled Electrically

Under the condition of the incident lightwave satisfying the wave-vector matching criteria,the surface waves even surface plasmons can be effectively excited on the surface of the metallic micro-nano-arrays(MMNAs),so as to form the needed resonant surface electromagnetic wave-field and surface electron density wave.By coupling the incident light energy into the surface of the MMNAs,the lightwave reflectivity and transmittance of the MMNAs can be significantly changed,and thus the lightwave transmission enhancement and then the reflection suppression based on the frequency selection can be realized according to the surface electron coupling and redistributing confinement of the surface electromagnetic wave-field excited.Research shows that both the spectrum and intensity of the excited surface plasmons are closely related to the factors such as the size,the morphology,the materials used and the dielectric behaviors of the MMNAs.The peak wavelength of the reflected lightwave or transmitted lightwave can be shifted by reasonably configuring the structural morphology and parameters of the MMNAs.Applying the signal voltage over the MMNAs,the different reflection or transmission operations can be generated based on the featured dielectric response of the polarized lightwave.In this thesis,the infrared antireflection and transmission enhancement of the MMNAs under the exciting surface wave or surface plasmons are studied carefully.The main work is as follows:Firstly,the dispersion relation of the surface plasmons propagating along the metal dielectric interface is analyzed based on the free electron gas model of metal.The excitation mode of the surface plasmons and their influence on the coupling resonance of the surface plasmons between the MMNAs are discussed.The mechanism of the polarization adjustment is studied according to the metallic nano-strip-arrays and then a kind of periodic MMNAs is designed.Then,based on the finite element method,several subwavelength nano-masks are designed.By adjusting the key parameters such as the metal film thickness,the cell period,the tip sharpness and its height,the infrared reflection and transmission and the local field enhancement and also the influence to excit the surface plasmons,are simulated and analyzed.The characteristics of the infrared transmission and reflection and surface charge distribution density,which are remarkably influenced by changing the linear polarization state of the incident lightwave and applying different signal voltages on the MMNAs,are discussed.Based on the structural simulation parameters,several samples are fabricated according to the common micro-nano-process technology,and their surface morphology tested by performing AFM and SEM measurements so as to acquire a set of micro-nano-structural parameters,and the technical process further optimized.The near-infrared transmission and reflection characteristics of the MMNAs are measured and analyzed using Fourier infrared micro-spectroscopy,the typical results of the antireflection and transmission enhancement being appeared at 2.6?m and 4.5?m.By loading the signal voltage on the MMNAs,the transmittance data about the orthogonal polarized lightwaves are acquired,and the transmittance variation owing to the applied signal voltage is observed,which means that an electrical adjustment of the transmitted lightwave polarization can be realized.By increasing the amplitude of the signal voltage applied,the transmitted lightwave polarization can be effectively controlled based on the variable transmittance characteristics of the incident lightwave with different linearly polarized state.