Ultrasensitive terahertz response mediated by split ring antenna induced giant resonant field enhancement
Jinhua Zhang,
Miao Cai,
Xingguo Zheng,
Dangdang Li,
Shuxiang Ma,
Xuebao Li,
Jingjing Fu,
Yinghao Yuan,
Lin Chen,
Xuguang Guo,
Yiming Zhu,
Songlin Zhuang
Affiliations
Jinhua Zhang
Shanghai Key Lab of Modern Optical Systems, Terahertz Technology Innovation Research Institute, and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Miao Cai
Shanghai Key Lab of Modern Optical Systems, Terahertz Technology Innovation Research Institute, and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Xingguo Zheng
Laboratory of Thin Film Optics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
Dangdang Li
Shanghai Key Lab of Modern Optical Systems, Terahertz Technology Innovation Research Institute, and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Shuxiang Ma
Shanghai Key Lab of Modern Optical Systems, Terahertz Technology Innovation Research Institute, and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Xuebao Li
Shanghai Key Lab of Modern Optical Systems, Terahertz Technology Innovation Research Institute, and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Jingjing Fu
Shanghai Key Lab of Modern Optical Systems, Terahertz Technology Innovation Research Institute, and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Yinghao Yuan
Shanghai Key Lab of Modern Optical Systems, Terahertz Technology Innovation Research Institute, and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Lin Chen
Shanghai Key Lab of Modern Optical Systems, Terahertz Technology Innovation Research Institute, and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Xuguang Guo
Shanghai Key Lab of Modern Optical Systems, Terahertz Technology Innovation Research Institute, and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Yiming Zhu
Shanghai Key Lab of Modern Optical Systems, Terahertz Technology Innovation Research Institute, and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Songlin Zhuang
Shanghai Key Lab of Modern Optical Systems, Terahertz Technology Innovation Research Institute, and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Optical resonators are widely utilized to enhance light–matter interaction by focusing electromagnetic waves into deep sub-wavelength regions. Here, we first present a metallic bowtie split ring (BSR) optical resonator as an asymmetric light coupler for a terahertz (THz) graphene photothermoelectric (PTE) detector. The giant THz field enhancement in the slit region of BSR is mediated by two types of resonances: the inductor–capacitor (LC) and the dipole resonances, which greatly increase the THz absorption, resulting in the sensitivity improvement of the THz PTE detector. In detail, the LC and dipole resonant behaviors of BSR are systematically investigated in both theoretical and experimental aspects. Compared with the dipole resonance, the LC resonance leads to stronger electric field localization and enhancement. An optimized BSR is designed and integrated with a graphene THz PTE detector, and an ultrasensitive THz PTE response is demonstrated. At room temperature and in zero-bias mode, the key detection parameters—responsivity, sensitivity (noise-equivalent power), and speed—are 138 V/W, 25 pW/Hz1/2, and 3.7 µs, respectively. Our results indicate that the LC resonance supported by BSR can introduce strong local field enhancement, which is helpful for realizing high sensitivity THz detectors.
