Leaky Surface Plasmon Polariton Modes at an Interface Between Metal and Uniaxially Anisotropic Materials

Abstract

By solving analytically derived characteristic equations, leaky surface waves are found to exist at an interface between a metal material and a uniaxially anisotropic dielectric material with its optic axis falling in the plane of the interface. Both the assumed lossless metal material with negative relative permittivity and the real metal such as silver having an imaginary part in its permittivity are considered to reveal the difference in the solved leakage loss behavior of the leaky modes. Analytical solutions are also confirmed by the finiteelement eigenmode analysis.

Surface plasmon polaritonig modes propagating along a metal thin film interfaced with uniaxially anisotropic material

“…Fig. 5 in [2] appears to be very similar to Fig. 3 in this paper, which is understandable since Figs.…”

“…The other remark relates to the comparison with Fig. 5 in [2], which shows the Re[n eff ] and the modal loss in dB/μm versus θ curves for the single interface between 5CB liquid crystal and silver, or removing the substrate in the structure of Fig. 3 and extending the silver thin film to become silver half space.…”

“…In [2], the complex effective indices of the SPP modes for the situation that the optic axis of the uniaxial material was rotated in the plane of the interface were obtained based on derived characteristic equations as well as by an FE eigenmode solver we developed. The two solution results were shown to agree with each other excellently.…”

“…The consideration of the dielectric being a uniaxially anisotropic material, e.g., the inclusion of liquid crystal, can be useful to designing tunable devices since the optic axis can be rotated by some suitable applied field with the corresponding effective refractive index varied. Recently, we have studied SPPs at an interface involving such uniaxial dielectric and demonstrated possible leaky-mode solutions [2]. Earlier, Li et al [3] reported the calculation of SPPs between a uniaxial crystal and a lossless (isotropic) metal, but only pure guided modes were solved.…”

“…Earlier, Li et al [3] reported the calculation of SPPs between a uniaxial crystal and a lossless (isotropic) metal, but only pure guided modes were solved. In [2], we have not only determined the leakage losses of the leaky modes but also taken the metal loss into account. In this paper, we extend our investigation to the structure of a metal thin film with cover and substrate materials, with the cover region being made of uniaxially anisotropic dielectric material.…”