Yuan Yifang, Zhang Jing, Li Chenyu, Li Hong, Han Yiping, Lou Jing
School of Physics, Xidian University, Xi'an 700071, China.
Air and Missile Defense College, Air Force Engineering University, Xi'an 710051, China.
Nanoscale. 2024 May 9;16(18):9068-9074. doi: 10.1039/d3nr06686j.
Active terahertz metasurface devices have been widely used in communication technology, optical computing and biosensing. However, numerous dynamically tunable metasurfaces are only operating at a single frequency point or in a narrow range, limiting the further possibility of the devices to meet contemporary broad-spectrum biosensing requirements. In this paper, a novel compact biosensor is proposed with an ultrawide resonance frequency agile channel shifted from 0.82 to 1.85 THz, with a tuning functionality up to 55.7%. In addition, under optical pumping irradiation, the modulator with ultra-fast response is able to complete the ultra-wideband resonant mode conversion from the Fano mode to the electromagnetically induced transparency (EIT) mode within 4 ps, and achieves a frequency shift sensitivity of 118 GHz RIU and 247 GHz RIU at 0.82 and 1.85 THz, respectively. This mechanism implements both refractive index and conductivity sensing functions, which provide a wealth of sensing information. Thus, this work presents the possibility of realising the detection of ultra-wide fingerprint spectra and can be extended to a wider range of optical fields.
有源太赫兹超表面器件已广泛应用于通信技术、光学计算和生物传感领域。然而，众多动态可调超表面仅在单个频率点或窄频段工作，限制了器件进一步满足当代广谱生物传感需求的可能性。本文提出了一种新型紧凑型生物传感器，其具有从0.82太赫兹到1.85太赫兹的超宽共振频率捷变通道，调谐功能高达55.7%。此外，在光泵浦照射下，具有超快响应的调制器能够在4皮秒内完成从法诺模式到电磁诱导透明（EIT）模式的超宽带共振模式转换，并分别在0.82太赫兹和1.85太赫兹处实现了118吉赫兹/RIU和247吉赫兹/RIU的频移灵敏度。该机制实现了折射率和电导率传感功能，提供了丰富的传感信息。因此，这项工作展示了实现超宽指纹光谱检测的可能性，并可扩展到更广泛的光学领域。
