Electromagnetically Induced Transparency and Fano Resonances Base on Coaxial Photonic Waveguide Made up of Asymmetric Loop and Resonators

Abstract

In the actual work, we present the phenomenon of electromagnetically induced transparency (EIT) and Fano resonances by one-dimensional microwave coaxial waveguides for the aim to achieve a filtering system either by transmission or by reflection with very high performance. Our proposed system is composed of coupled asymmetric loops of lengths d2 and d3, and two asymmetric resonators of lengths d5 and d6. This system creates the resonance modes, which are sensitive to certain lengths, while they are insensitive to other lengths. The very narrow EIT resonance appears as a maximum transmission peak stuck between two transmissions zeros, this EIT is due to the interaction of the Eigen modes of symmetric resonators and the incident electromagnetic waves. On the other hand, a resonance near to a zero of transmission is called a Fano resonance, its appearance is due to the interaction between the Eigen modes of symmetric loops and the incoming electromagnetic waves. The theoretical results are obtained using the continuous medium interface response theory, which allows calculating the Green function of composite systems and the transmission rate T. This structure can be utilized for electromagnetic filtering by transmission or reflection with high transmittance and good quality factor. According to these results, this filtering system can be used in the field of microwave communication antennas.

Electromagnetically Induced Transparency and Fano Resonances in Waveguides and U-shaped or Cross-shaped Resonators

“…Their study has spread to other fields, with promising applications in the control of slow light. These phenomena are not limited to atomic systems and have been extensively studied in classical systems, including photonic waveguides [4][5][6]. An example of EIT resonance occurs in opaque atomic media.…”

Tunable Filters Based on Fano Resonance Using Asymmetric Moving Resonators in a Single Loop System

“…Numerous filters based on waveguide systems have been proposed and manufactured to control and select several frequencies. Photonic waveguides system can be considered as one of the most recent photonic technologies because of its extraordinary photonic properties for a set of applications [1][2][3][4][5][6][7]. The photonic waveguide structures have attracted important attention by the scientific community due to their ability to guide and confine the electromagnetic waves [8].…”

“…This structure contains four segments of the same lengths, and asymmetric resonators are moving in the system. Based on the scientific literature, such type of waveguides non-periodical structure based on the loop and resonators (if we consider either the resonator or the loop) has the capacity to create Fano resonances in the transmission spectrum [5]. These Fano resonances can be used to realize devices such as electromagnetic switches, lasers, sensors, ultrafast switches, and slow-electromagnetic wave's devices [19][20][21][22].…”