• Acta Physica Sinica
  • Vol. 68, Issue 20, 208501-1 (2019)
Qing-Chen Niu, Jun Gou*, Jun Wang, and Ya-Dong Jiang
DOI: 10.7498/aps.68.20190902 Cite this Article
Qing-Chen Niu, Jun Gou, Jun Wang, Ya-Dong Jiang. Absorption enhancement of terahertz wave in microbolometers by titanium disk array[J]. Acta Physica Sinica, 2019, 68(20): 208501-1 Copy Citation Text show less

Abstract

In this paper, a two-dimensional subwavelength periodic titanium (Ti) disk array integrated in micro-bridge structure is proposed to enhance the absorption of terahertz (THz) microbolometer. Based on the rigorous coupled wave analysis (RCWA) method, THz absorption characteristics of Ti disk arrays with different structure parameters in micro-bridge structure arrays are studied. Periodic disk array structure reduces the surface plasmon frequency of Ti, excites the spoof surface plasmons in the THz band and leads to resonance enhanced absorption. The resonance absorption frequency is determined by the structural parameters of Ti disk array including period and diameter while the absorption rate of THz wave is greatly affected by the thickness of Ti disks. The resonant cavity in micro-bridge structure can reduce the resonance frequency and enhance the coupling efficiency. The micro-bridge structure designed in this paper breaks the diffraction limit and traps the THz wave with a small period (37 μm). An absorption of nearly 90% is achieved at 3.5 THz. The structure meets the requirements of small size, high absorption and good process compatibility of the THz microbolometer.
Qing-Chen Niu, Jun Gou, Jun Wang, Ya-Dong Jiang. Absorption enhancement of terahertz wave in microbolometers by titanium disk array[J]. Acta Physica Sinica, 2019, 68(20): 208501-1
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