Photonics Structure And Properties Of Multi - Walled Carbon Nanotube Arrays

Carbon nanotubes are considered to be a major breakthrough of modern materials science because of its unique geometry structure and fantastic physical, chemical properties. As is known to all, multi-walled carbon nanotubes are composed of two or more rolled-up graphene layers with different diameter. The structure can be regarded as photonic crystal which is of periodically placed multi-walled carbon nanotube on the order of wavelength. The physical model is established and the steady field is studied and analyzed by using a finite element method in this paper.Considering the anisotropic and wavelength dependent of the dielectric function, the Lorentz-Drude(LD) oscillator model was utilized to study photonic properties for multi-walled carbon nanotube arrays in both TE and TM polarizations. The calculated results obviously show that there is a plasmonic filtering response toward TE polarized light.Waveguide with defects in Multi-walled carbon nanotube arrays is studied through the transmission spectrum and electric field distribution. In employed structure the specific frequency light is confined in the defect with the photonic band gap effect and travels along the direction of defect. According to different polarizations vary in terms of sensitivity to defects, we designed a kind of polarization beam splitter based on multi-walled carbon nanotube arrays which has low loss and low crosstalk, as well as broad operating wavelength.A stationary solver is utilized to solve the nonlinear eigenvalue problem by using the finite element, then dispersion relation curves for the designed structure are calculated so as to get propagation constants for different excited mode. Then, the basic principle of self-imaging is predicted theoretically. It is confirmed and analyzed that self-imaging induced by multi-mode interference in multi-walled carbon nanotube arrays at visible wavelengths by establishing models. Numerical simulation results agree well with theoretical expectations. Imaging positions and Talbot distances increase with the radius of carbon nanotube in multimode waveguides on basis of analyses.