Adjustable transmission properties through ring-shaped nanotube arrays using finite-difference time-domain method

ZHOU Feng-qi(周凤麒)¹, LIU Zhi-min(刘志敏)^{1, 2}, LI Hong-jian(李宏建)^{2, 3}, LIU Er-gen(刘二根)¹

(1. College of Sciences, East China Jiaotong University, Nanchang 330013, China;
2. College of Physics Science and Technology, Central South University, Changsha 410083, China;
3. College of Materials Science and Engineering, Central South University, Changsha 410083, China)

Abstract:Metallic ring-shaped nanotube arrays are proposed and its optical transmission properties are studied by using finite-difference time-domain (FDTD) method. Compared with the transmission spectra of conventional circular nanotube arrays, two photonic band gaps are emerged in the transmission spectra of ring-shaped nanotube arrays, the two band gaps and transmission spectra are adjusted by the length, inner radius, intertube spacing and the dielectric constants of the core and embedding medium, and magnitude modification, redshift and blueshift of the resonance modes are observed. A metallic ring-shaped nanotube arrays for subwavelength band-stop filter in the range of visible light can be achieved. To understand its physical origin, field-interference mechanism was suggested by the field distributions. The proposed nanostructures and results may have great potential applications in subwavelength near-field optics.

Key words:ring-shaped nanotube arrays; plasmon; transmission spectrum; finite-difference time-domain (FDTD); optimization