Metal nanoparticles and nanowires (columns), and other nanostructures can also be used to generate surface plasmon resonance [11�C13]. In this paper, SPR sensors based on PCF filled with different numbers of silver nanowires have been analyzed though the finite element method (FEM) by using COMSOL Multiphysics software, regularity of the resonant new post wavelength changing with refractive index of the sample has been numerically simulated, and resonant wavelength detection as well as Inhibitors,Modulators,Libraries intensity detection sensitivity have also been discussed. Numerical results show that the sensitivity will increase with the increase of relative distance between two silver nanowires within 2 ��m, and then it tends to be stable with the continued increase.
The spectral and intensity sensitivity of the grapefruit PCF filled with more silver nanowires is better than the one filled with less. Moreover, as Inhibitors,Modulators,Libraries the air holes of grapefruit PCF are large enough, the fabrication is expected to be easy.2.?Numerical Simulation and Analysis2.1. SPR Sensors Based on PCFs Filled with One Silver Nanowire of 300 nm RadiusWe utilize the self-designed grapefruit PCF made of silica in the simulation [14]. The diameter of the core is approximately 10 microns and the large hole of the PCF is easy to Inhibitors,Modulators,Libraries fill for measuring fluid samples. The structure of the PCF is shown in Figure 1, with each grapefruit hole occupied by one silver nanowire of 300 nm radius. The refractive index of the fused silica optical fiber can be determined by the Sellmeier equation and for the relative dielectric constant of silver we referred to the Handbook of Optics [15].
In recent years, PCF-based SPR sensors used in refractive index sensing of aqueous analytes have attracted much Inhibitors,Modulators,Libraries attention [16,17]. All holes are filled with liquid samples (na = 1.33) in this paper.Figure 1.(a) Structure diagram of the grapefruit PCF occupied by silver nanowires (indicated by blue dots) of 300 nm; (b) Optical field distribution of the fundamental mode (the wavelength of the incident light is 600 nm); (c) Structure diagram of the grapefruit …We use the finite element method (FEM) to solve the light field mode and calculate the attenuation constant of the fundamental mode of fiber with different mosaic structures of silver nanowires (optical field distribution of the fundamental mode is shown in Figure 1(b), and the arrow indicates the polarization direction of magnetic field).
The attenuation constant of the fundamental mode is calculated for different wavelengths of incident light. The wavelength with maximal transmission loss can be identified and light Dacomitinib intensity detection sensitivity at different wavelengths can also be investigated. It is easy to prove that the power attenuation coefficient �� is:��=2k0Im(neff)(1)where k0 is the wave number (k0 = 2e/?), neff is the mode effective refractive index, the real part expressed the dispersion and the imaginary part selleck Dasatinib expressed the transmission loss.