Abstract-Meander Line Nanoantenna Absorber for Subwavelength Terahertz Detection

Yuyao Chen,  Haoran Zhou, Xiaochao Tan, Shun Jiang,  Ao Yang, Junyu Li, Mingming Hou,  Qiushi Guo, Shao-Wei Wang,  Feng Liu, Huan Liu, Fei Yi

https://ieeexplore.ieee.org/document/8370898/

The detection of terahertz electromagnetic waves is crucial for emerging applications within this frequency band, such as spectroscopy, imaging and communication. Extending the well-developed uncooled infrared focal plane array technology to terahertz frequency regime would be very attractive, but high absorption in the terahertz region with a subwavelength pixel is necessary. In this paper, we proposed a meander line nanoantenna(MLNA) absorber with a metal-insulator-metal structure for sub-wavelength terahertz absorption. 89% absorption is achieved at the wavelength of 155 μm with a 10 μm pitch size. The MLNA absorber is polarization insensitive and can maintain a high absorption when the incident angle is within 40 degrees. We expect that the proposed MLNA absorber can be integrated with the small pixels of uncooled infrared focal plane array for terahertz detection.

Abstract-Toward Sensitive Room-Temperature Broadband Detection from Infrared to Terahertz with Antenna-Integrated Black Phosphorus Photoconductor

http://onlinelibrary.wiley.com/doi/10.1002/adfm.201604414/abstract;jsessionid=6D6EEA515BD415551858CA0C703C0EFC.f01t01?systemMessage=Wiley+Online+Library+Journal+subscribe+and+renew+pages+for+some+journals+will+be+unavailable+on+Wednesday+11th+January+2017+from+06%3A00-12%3A00+GMT+%2F+01%3A00-07%3A00+EST+%2F+14%3A00-20%3A00+SGT+for+essential+maintenance.+Apologies+for+the+inconvenience

Graphene-like two-dimensional materials (graphene, transition-metal dichalcogenides (TMDCs)) have received extraordinary attention owing to their rich physics and potential applications in building nanoelectronic and nanophotonic devices. Recent works have concentrated on increasing the responsivity and extending the operation range to longer wavelengths. However, the weak absorption of gapless graphene, and the large bandgap (>1 eV) and low mobility in TMDCs have limited their spectral usage to only a narrow range in the visible spectrum. In this work, we demonstrate for the first time a high-performance, antenna-integrated, black phosphorus (BP)-based photoconductor with ultra-broadband detection from the infrared to terahertz frequencies. The good trade-off between the moderate bandgap and good mobility results in a broad spectral absorption that is superior to that of graphene. Different photoconductive mechanisms, such as photothermoelectric (PTE), bolometric, and electron–hole generation can be distinguished depending on the device geometry, incident wavelength, and power. Especially, the photoconductive response remains highly efficient, even when the photon energy is extended to the terahertz (THz) band at room temperature, which is driven by the thermoelectric-induced well. The proposed photodetectors have a superior performance with an excellent sensitivity of over 300 V W−1, low noise equivalent power (NEP) (smaller than 1 nW Hz−0.5(10 pW Hz−0.5) with respect to the incident (absorbed) power), and fast response, all of which play key roles in multispectral biological imaging, remote sensing, and optical communications.