Computational surface plasmonic micro-device for sub-wavelength switching and sensing applications

摘要

In this paper, the cross coupling between two surface plasmon polariton waveguide is designed by the cross coupling mode theory, where the output results are computed and obtained by the MATLAB program. The two vertical metal-dielectric waveguides of silicon waveguides with the gold thin films on the tops are performed, where such a device is known as a coupler. The other simulation program is the Opti-wave, which is used a finite difference time domain method. Simulation results obtained have shown that the behavior as the cross coupling transverse mode of surface plasmon polariton between the two waveguides occurs. The other forms of surface plasmon polariton couplers are 1 × 2, 2 × 1 and 2 × 2 couplers, which are designed and manipulated using the Opti-wave software, where the results are agreed well with the mathematical computation of the coupling length L_c, in which the H_y and E_z peak oscillations are agreed well with the mathematical computation of the coupling length (L_c). The switching and sensing aspects of the device are also simulated and interpreted, from which the result shows that the H_y amplitude is linear relationship to the dielectric gap refractive index between the two surface plasmon polariton waveguides, where the coupling length is fixed. From the simulation results, it is found that such a proposed device has the potential of using for liquid switching and sensing applications within micrometer scale.