Design And Numerical Simulation Of Optical Filter And Metamaterial Perfect Absorber Based On Surface Plasmon Polaritons

In recent years, surface plasmon polaritons (SPPs) have attract considerable interest in scientific community due to their unique optical properties. SPPs have extensive applications in many fields of scientific practice, such as environment energy, biology technology, and optical imaging. In order to broaden these applications, more micro-nano optical devices with good properties based on SPPs must be designed. Experimental preparation of micro-nano optical devices takes much time and cost. However, the numerical calculations of micro-nano optical devices are relatively cheap and efficient. In this thesis, we mainly elaborate the design and simulation of optical filters and metamaterial perfect absorbers using finite-difference time-domain (FDTD) method. The contents of this thesis are listed as following:In chapter1, the basic concepts of the propagative surface plasmon and localized surface plasmon are briefly reviewed. Moreover, we review the application of the surface plasmon polaritons on the silicon-based solar cells. At last, we introduce the concept of finite-difference time-domain method.In chapter2, we investigate the optical properties of two optical filters based on extraordinary optical transmission (EOT). The transmission of the periodic metallic subwavelength hole array is greater than the predicted value based on classic electromagnetic theory, even exceed the ratio of the hole area to the unit cell area. The phenomenon of EOT can be utilized to make optical filter. We propose two designs of optical filters, in which one is a gold film with two different subwavelength hole arrays on two sides, and the other is the subwavelength array based on the composite hole-pillar structure. We calculate the transmission of the two optical filters in the visible and infrared regions using the commercial package FDTD Solutions. In the optical simulations, it is found that the strength and the position of the transmission peaks of both optical filters can be effectively manipulated through changing some geometrical parameters. In the first designed optical filter, the energy level of (1,0) mode associated with the propagative surface plasmon is splitted. When the incident light illuminate the gold film surface with the non-penetrating hole array, with the depth of the non-penetrating holes increases, the peaks of (1,1) mode associated with the propagative surface plasmon polaritons are enhanced as well as the peak positions shift to the longer wavelengths. When the incident light illuminate the gold film surface without the non-penetrating hole array, with the depth of the non-penetrating holes increases, the peaks of (1,1) mode associated with the propagative surface plasmon polaritons are enhanced first and then suppressed. In the second optical filter, there are two strong peaks. The peak with long wavelength is associated with the surface plasmon polariton resonance at the gold-silica interface. The peak with short wavelength is associated with the magnetic dipole resonance of the silicon pillars. Moreover, there are two weak peaks, corresponding to the magnetic quadrupole resonance and the coupling between the whispering-gallery mode and magnetic dipole. In the calculations, it is found that the magnetic dipole resonance of the silicon pillars suppresses the surface plasmon polariton resonance at the gold-air interface.In chapter3, the matematerial perfect absorber based on the insulator-insulator-metal structure is proposed. In the simulations, it is found that the insulator-insulator-metal structured matematerial perfect absorber exhibit dual band perfect absorption in the visible and infrared regions. Under the help of Maxwell equations, it is found that the incident light illuminates the silicon nitride particles causing the electric dipole resonances in the particles. The displacements of the electric dipole resonances cause the loop polarization currents. The polarization currents in the bottom surfaces of the silicon nitride particles cause the distributions of the polarization charge which induce the mirror polarization charge in the top surface of the gold film. The oscillation of the mirror polarization charge in the top surface of the gold film causes the propagative surface plasmon. As a result, the incident light is transformed into the propagative surface plasmon, thus the energy of the incident light is trapped in the silica film or the silicon nitride particle array. Moreover, the insulator-insulator-metal structured matematerial perfect absorber can be used to make optical sensor.In chapter4, we design the optical filter based on composite hole-pillar structure in the microwave band. We insert the iron pillars into the centimeter sized metallic hole array, forming the coaxial gap array. In the experiment, we observe the transmission up to90%. A simple model is proposed to explain the high-through transmission. It is found that the incident electromagnetic wave illuminates the sample, causing the electric dipole resonance of the iron pillar. The radiation of the subwavlength hole is equal to the radiation of the magnetic dipole. The electric dipole resonance of the iron pillar causes the magnetic field which enhances the magnetic dipole radiation of the subwavlength hole. As a result, the energy of the incident light highly passes through the gap array.In chapter5, we presented a general summary of this thesis and some potential topics for future.