Switchable Broadband Terahertz Absorber Based on Temperature Control

Guang Zhu; Yuehua Huo; Yanqiong Shi

doi:10.3788/LOP202158.1316001

Journals >Laser & Optoelectronics Progress >Volume 58 >Issue 13 >Page 1316001 > Article

Laser & Optoelectronics Progress
Vol. 58, Issue 13, 1316001 (2021)

Switchable Broadband Terahertz Absorber Based on Temperature Control

Guang Zhu^{1、2、3、*}, Yuehua Huo⁴, and Yanqiong Shi^1、2、3

Author Affiliations

¹School of Mechanical and Electrical Engineering, Anhui Jianzhu University, Hefei , Anhui 230601, China

²Key Laboratory of Construction Machinery Fault Diagnosis and Early Warning Technology, Anhui Jianzhu University, Hefei , Anhui 230601, China

³Key Laboratory of Intelligent Manufacturing of Construction Machinery, Hefei , Anhui 230601, China

⁴Network and Information Center, China University of Mining and Technology-Beijing, Beijing 100083, China

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DOI: 10.3788/LOP202158.1316001 Cite this Article Set citation alerts

Guang Zhu, Yuehua Huo, Yanqiong Shi. Switchable Broadband Terahertz Absorber Based on Temperature Control[J]. Laser & Optoelectronics Progress, 2021, 58(13): 1316001 Copy Citation Text

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Abstract

To realize the dynamic adjustable function of the broadband absorber, this paper proposes and designs a symmetrical absorber structure composed of a square top layer with embedded cross, a SiO₂ dielectric layer, and a VO₂ bottom layer. In the range from 2 THz to 4 THz, the absorption efficiency of the device can be adjusted from less than 10% to more than 90% by adjusting the conductivity of the bottom layer of VO₂, and its switching modulation depth is greater than 65%. In a wide frequency range, the device can be dynamically switched between the reflector and perfect absorber modes. The simulation results show that the absorber has wide-angle and polarization-insensitive characteristics, and the incident angle range of electromagnetic waves to the absorber can reach 75°. Based on the above advantages, the absorber has great potential in terahertz device applications such as smart attenuators, reflectors, and spatial modulators.

Keywords

broadband absorber materials polarization insensitive characteristics switchable function terahertz vanadium dioxide

ε_{e f f}^{B R} = \frac{1}{4} [ε_{a} (2 - 3 f_{V O_{2}}) + ε_{b} (3 f_{V O_{2}} - 1) + \sqrt[]{8 ε_{a} ε_{b} + ε_{a} (2 - 3 f_{V O_{2}}) + ε_{b} {(3 f_{V O_{2}} - 1)}^{2}}]

，（1）

ε_{b} (ω) = ε_{(\infty)} - \frac{ω_{p}^{2} (σ)}{ω (ω + i / τ)}

，（2）

σ_{m} = - i ε_{0} ω (ε_{b} - 1)

。（3）

f (T) = f_{V O_{2} - m a x} \{1 - \frac{1}{1 + e x p [(T - T_{0}) / Δ T]}\}

，（4）

S_{11} = \frac{Z - Z_{0}}{Z + Z_{0}}

，（5）

z = \pm \sqrt[]{\frac{{(1 + S_{11})}^{2} - S_{21}^{2}}{{(1 - S_{11})}^{2} - S_{21}^{2}}}

，（6）

n = \pm \frac{1}{k d} a r c c o s [\frac{1}{2 S_{21}} (1 + S_{21}^{2} - S_{11}^{2})]

，（7）

Guang Zhu, Yuehua Huo, Yanqiong Shi. Switchable Broadband Terahertz Absorber Based on Temperature Control[J]. Laser & Optoelectronics Progress, 2021, 58(13): 1316001

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