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Sun T, Bai Z, Li Z, Liu Y, Chen Y, Xiong F, Chen L, Xu Y, Zhang F, Li D, Li J, Zhao W, Nie T, Wen L. Generation of Tunable Terahertz Waves from Tailored Versatile Spintronic Meta-Antenna Arrays. ACS APPLIED MATERIALS & INTERFACES 2023; 15:23888-23898. [PMID: 37130032 DOI: 10.1021/acsami.3c00315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Broadband spintronic terahertz (THz) radiation can be efficiently generated by spin-to-charge current conversion in a ferromagnetic/nonmagnetic heterostructure. There had been many studies on realizing the enhancement or the modulation of spintronic terahertz waves. However, reported devices so far focus on implementing certain specific modulation methods, either related to the spintronic stacks or related to the metamaterial structures. In this study, a set of femtosecond laser-driven versatile spintronic terahertz devices are proposed by integrating meta-antenna structures with W/CoFeB/Pt nanolayer stacks. These monolithic integrated devices exhibit spintronic terahertz wave emission, spectral modulation, and polarization manipulation simultaneously. The terahertz pulses are generated within the ferromagnetic heterostructure interfaces and transmitted along the metallic structures, leading to the modulation of the spintronic terahertz waves. Results have shown that the center-frequency shift is up to 140 GHz and the value of ellipticity can reach 0.6, demonstrating a set of integrated and efficient spintronic terahertz devices to modulate the emitted wave. In addition, compared with the slotline antenna, the maximum peak value of the bandpass band is enhanced up to 1.63 times by carefully designing the metamaterial structure. The spintronic meta-antenna array proposed here paves an integrated way for the manipulation of spintronic terahertz optoelectronic devices.
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Affiliation(s)
- Tong Sun
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
- Shenzhen Institute of Beihang University, Shenzhen 518057, China
- Beihang Hangzhou Innovation Institute Yuhang, Beihang University, Hangzhou 310023, China
| | - Zhongyang Bai
- School of Electrical Information Engineering, Beihang University, Beijing 100191, China
- Shenzhen Institute of Beihang University, Shenzhen 518057, China
| | - Zhaoying Li
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
- Shenzhen Institute of Beihang University, Shenzhen 518057, China
- Beihang Hangzhou Innovation Institute Yuhang, Beihang University, Hangzhou 310023, China
| | - Yongshan Liu
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
- Hefei Innovation Research Institute, Beihang University, Hefei 230013, China
| | - Yaxuan Chen
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
- Shenzhen Institute of Beihang University, Shenzhen 518057, China
- Beihang Hangzhou Innovation Institute Yuhang, Beihang University, Hangzhou 310023, China
| | - Fan Xiong
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
- Shenzhen Institute of Beihang University, Shenzhen 518057, China
| | - Linliang Chen
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
- Shenzhen Institute of Beihang University, Shenzhen 518057, China
| | - Yong Xu
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
- Hefei Innovation Research Institute, Beihang University, Hefei 230013, China
| | - Fan Zhang
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
- Hefei Innovation Research Institute, Beihang University, Hefei 230013, China
| | - Dong Li
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
| | - Junze Li
- Microsystem & Terahertz Research Center, China Academy of Engineering Physics, Chengdu 610200, China
| | - Weisheng Zhao
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
| | - Tianxiao Nie
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
- Beihang Hangzhou Innovation Institute Yuhang, Beihang University, Hangzhou 310023, China
- Hefei Innovation Research Institute, Beihang University, Hefei 230013, China
| | - Lianggong Wen
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
- Shenzhen Institute of Beihang University, Shenzhen 518057, China
- Beihang Hangzhou Innovation Institute Yuhang, Beihang University, Hangzhou 310023, China
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Zhang G, Fang Q, Li Y, Yang J, Hu M, Li J, Deng G, Yin Z, Lu H. Manipulation of sub-terahertz waves using digital coding metasurfaces based on liquid crystals. OPTICS EXPRESS 2023; 31:9428-9436. [PMID: 37157514 DOI: 10.1364/oe.486146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
This paper presents a novel sub-terahertz liquid crystal (LC) phase shifter based on digital coding metasurfaces. The proposed structure consists of metal gratings and resonant structures. They are both immersed in LC. The metal gratings function as reflective surfaces for electromagnetic waves and electrodes for controlling the LC layer. The proposed structure changes the state of the phase shifter by switching the voltage on every grating. It allows the deflection of LC molecules within a subregion of the metasurface structure. Four switchable coding states of the phase shifter are obtained experimentally. The phase of the reflected wave varies by 0°, 102°, 166°, and 233° at 120 GHz. Due to the presence of the transverse control electric field, modulation speed is approximately doubled compared to the free relaxation state. This work provides a novel idea for wavefront modulation of phase.
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