A high-refractive-index dielectric particle with the ability of supporting both electric and magnetic resonances, operating at 1-2 terahertz, is proposed. It is shown that the suggested omega-shaped nanoparticle is able to control the resonance frequencies independently by changing geometrical dimension. It is also demonstrated numerically that an asymmetric omega particle shows a tunable radiation pattern, depending on the incident frequency. The radiation beam can steer in the range of +/- 30 degrees. The omega particle shows a directive radiation pattern with small back radiation, due to the constructive interference of the induced electric and magnetic moments. Therefore, the application of the proposed antenna in directivity enhancement is considered. Then, in order to achieve high directivity, omega particles are arranged in an array. Their employment for directivity enhancement has led to the maximum directivity of 11.8 dB. Side-lobe level has the minimum amount of -18.3 dB, and total size of the structure is 400 mu m x 400 mu m congruent to 2.6 lambda x 2.6 lambda in the x-y plane, while it does not exceed a quarter of a wavelength in height. (c) 2018 Optical Society of America
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机译：提出了一种高折射率介电颗粒，其具有支撑在1-2Terahertz的电磁共振的能力，以1-2张Terahertz。结果表明，建议的ω形纳米颗粒能够通过改变几何尺寸来独立地控制谐振频率。在数值上还在上表现出不对称的ω颗粒表示可调谐辐射图案，这取决于入射频率。辐射束可以转向+/- 30度的范围。由于诱导电和磁矩的建设性干涉，ω粒子表示具有小后辐射的指示辐射图案。因此，考虑了所提出的天线在方向性增强中的应用。然后，为了实现高方向性，ω颗粒布置在阵列中。他们对方向性增强的就业导致了11.8 dB的最大方向性。侧瓣级别的最小金额为-18.3 dB，结构总尺寸为400 mu mx 400 mu m一致到xy平面中的2.6λx 2.6 lambda，而它不超过高度波长的四分之一。 （c）2018年光学学会
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