Tunable beam propagation based on cylindrically symmetric gradient index system

Abstract

In this work, a cylindrical symmetric gradient-index two-dimensional electromagnetic systems is constructed by using of the magnetic metamaterials consisting of an array of ferrite rods. With the change of the bias magnetic field the different gradient-index systems can be obtained, based on which a flexible beam steering is demonstrated. Based on the effective-medium theory, the effective electric permittivity and the effective magnetic permeability can be retrieved and thus the effective refractive index is obtained straightforwardly. It is shown that with the variation of the ferrite rod radius the effective index profile with particular gradient can be realized, which exhibits the electromagnetic "black hole" like effect. Especially, the gradient index profile is also designed by introducing the gradient bias magnetic field, which, in principle, results in the refractive index profile with many different gradients. Finally, the propagation of a Gaussian beam in the gradient-index systems is simulated with the use of multiple scattering theory. A few different phenomena are observed such as the "black hole" effect, the interior beam deflection, the exterior beam deflection, and the beam splitting. Furthermore, the functionalities can be switched between each other by controlling the bias magnetic field, adding an additional degree of freedom for beam steering.

Apiaceae Medicinal Plants in China: A Review of Traditional Uses, Phytochemistry, Bolting and Flowering (BF), and BF Control Methods

“…Hangbaizhi; isoimperatorin (4) in Angelica dahurica, Angelica dahurica cv. Hangbaizhi, Notopterygium franchetii, and Notopterygium incisum; nodakenin (5) in Angelica decursiva, Notopterygium franchetii, and Notopterygium incisum; notopterol (8) in Notopterygium franchetii and Notopterygium incisum; and praeruptorin A (9) and praeruptorin B (10) in Peucedanum praeruptorum (see Table 2 and Figure 5) [18].…”

“…The occurrence of bolting and flowering (BF) plays a critical role in the transition from vegetative growth to reproductive development in the plant life cycle [7]. However, BF significantly reduces the accumulation of metabolites in vegetative organs, which ultimately leads to the lignification of rhizomes and/or roots such as sugar beet [8], lettuce [9], and Chinese cabbage [10]. In particular, it common that BF significantly reduces the yield and quality of the rhizomatous AMPs [11].…”