Universal coupled theory for metamaterial bound states in the continuum

Wei Huang,Yu Cheng,Shan Yin,Wentao Zhang,Songyi Liu,Jiaguang Han

doi:10.1088/1367-2630/ac20e9

Wei Huang, Yu Cheng + Show 4 more

Open Access

https://doi.org/10.1088/1367-2630/ac20e9

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Abstract

In this paper, we present a novel universal coupled theory for metamaterial bound states in the continuum (BIC) or quasi-bound states in the continuum (quasi-BIC) which provides ultra-high Q resonance for metamaterial devices. Our theory analytically calculates the coupling of two bright modes with phase information. Our method has much more accuracy for ultra-strong coupling comparing with the previous theories (the coupling of one bright mode and one dark mode and the two bright-mode coupling). Therefore, our theory is much more suitable for BIC or quasi-BIC and we can accurately predict the transmission spectrum of metamaterial BIC or quasi-BIC for the first time.

Highlights

Bound states in the continuum (BIC) is initially proposed in quantum mechanics [1], which trapped or guided modes with their frequencies in the frequency intervals of radiation modes [2]
We present a novel universal coupled theory for metamaterial Bound states in the continuum (BIC) or quasi-Bound states in the continuum which provides ultra-high Q resonance for metamaterial devices
This paper proposes a brand universal coupled theory for metamaterial BIC, which contains the coupling between two bright modes with phase

Summary

INTRODUCTION

Bound states in the continuum (BIC) is initially proposed in quantum mechanics [1], which trapped or guided modes with their frequencies in the frequency intervals of radiation modes [2]. The BIC phenomenon can vastly increase the Q-value resonance, especially for the metamaterial, due to the high loss of a single metamaterial structure. We can not fabricate infinite Q-value resonance for the metamaterial It can still provide a very high Q value for the metamaterial device, and can widely be used in various applications. Our theory can predict a very high Q-valve situation and the parameters of our view come from the fundamental physical parameters of metamaterial, such as the resonance frequency ω1, ω2 for each single metamaterial structure, the loss γ1, γ2 for each single metamaterial structure and the phase φ1 and φ2 with each resonance frequency for each single metamaterial structure. The beauty of our theory is that the resonance frequencies, the loss and the phases are obtained by the spectrum of each signal metamaterial structure, and coupling strength describes the connection of two. We predict the frequency of BIC and Q-value from the spectrum of transmission THz wave, as shown in Fig. 1 (c)

UNIVERSAL COUPLED THEORY

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DISCUSSION

CONCLUSION