Zhang Yong Gang, Liu Wei, Yao Hai Yun, Liang Lan Ju, Yan Xin, Zong Ming Ji, Gao Shan, Huang Cheng Cheng, Qiu Fu, Feng Zhen Wei, Zhang Rui, Hu Xiao Fei, Li Zhen Hua, Wang Zi Qun
Appl Opt. 2024 Feb 10;63(5):1306-1312. doi: 10.1364/AO.509826.
A broadband and narrowband switchable terahertz (THz) absorber based on a bulk Dirac semimetal (BDS) and strontium titanate (STO) is proposed. Narrowband and broadband absorption can be switched by adjusting the Fermi level of the BDS. When the Fermi level of the BDS is 100 meV, the device is an absorber with three narrowband absorption peaks. The frequencies are 0.44, 0.86, and 1.96 THz, respectively, when the temperature of STO is 250 K. By adjusting the temperature of STO from 250 to 500 K, the blue shifts of the frequencies are approximately 0.14, 0.32, and 0.60 THz, respectively. The sensitivities of the three absorption peaks are 0.56, 1.27, and 2.38 GHz/K, respectively. When the Fermi level of the BDS is adjusted from 100 to 30 meV, the device can be switched to a broadband absorber with a bandwidth of 0.70 THz. By adjusting the temperature of STO from 250 to 500 K, the central frequency shifts from 1.40 to 1.79 THz, and the bandwidth broadens from 0.70 to 0.96 THz. The sensitivity of the central frequency is 1.57 GHz/K. The absorber also has a wide range of potential applications in multifunctional tunable devices, such as temperature sensors, stealth equipment, and filters.
提出了一种基于体狄拉克半金属（BDS）和钛酸锶（STO）的宽带和窄带可切换太赫兹（THz）吸收器。通过调节BDS的费米能级可以实现窄带和宽带吸收的切换。当BDS的费米能级为100 meV时，该器件是一个具有三个窄带吸收峰的吸收器。当STO的温度为250 K时，频率分别为0.44、0.86和1.96 THz。通过将STO的温度从250 K调节到500 K，频率的蓝移分别约为0.14、0.32和0.60 THz。三个吸收峰的灵敏度分别为0.56、1.27和2.38 GHz/K。当BDS的费米能级从100 meV调节到30 meV时，该器件可以切换为带宽为0.70 THz的宽带吸收器。通过将STO的温度从250 K调节到500 K，中心频率从1.40 THz移至1.79 THz，带宽从0.70 THz拓宽到0.96 THz。中心频率的灵敏度为1.57 GHz/K。该吸收器在多功能可调谐器件中也具有广泛的潜在应用，如温度传感器、隐身设备和滤波器。
