基于超表面微辐射热计的双色偏振探测器

Dual-Band Polarization Detector Based on Metasurface Microbolometer

介绍了利用超表面吸收体即具有亚波长尺寸和间距的光学谐振器阵列来取代分立的滤光片和偏振片实现了氧化钒(VO x)微测辐射热计对光谱和偏振的同时选择。超表面吸收体选择性地吸收特定波段的TM偏振光而反射TE偏振光,其中特定波段的中心波长和带宽可人为调动。针对5.3~6.6μm和6~7.4μm两个红外波段分别设计制备了超表面吸收体,制备出的超表面吸收体对TM偏振光的吸收率分别为0.8322和0.7720,偏振消光比分别为42.24和42.65。并将超表面吸收体与氧化钒微测辐射热计进行了集成,测试得到的探测器响应谱与超表面吸收体的吸收谱能够较好地吻合。制备出的两种探测器的峰值响应度分别为1.0V/W和1.46V/W,分别位于6.0μm和6.8μm处。同时两个探测器的峰值探测率分别为6.94×10^(5)cm·Hz^(1/2) W^(-1)和9.95×10^(5)cm·Hz^(1/2) W^(-1),工作频率分别为11Hz和36Hz。我们的工作为实现大面阵室温多光谱偏振成像探测器提供了一种新的方法。

We report using metasurface absorbers,that is,optical resonator arrays with sub-wavelength sizes and spacings,to replace discrete filters and polarizers to achieve simultaneous selection of spectrum and polarization for Vanadium oxide(VO x)microbolometers.The metasurface absorber selectively absorbs TM polarized light in a specific band and reflects TE polarized light,in which the center wavelength and bandwidth of the specific band can be artificially adjusted.The metasurface absorbers are designed and prepared for the two infrared bands of 5.3~6.6μm and 6~7.4μm,respectively.The absorption rates of the prepared metasurface absorbers to TM polarized light are 0.8322 and 0.7720,respectively,and the polarization extinction ratios are 42.24 and 42.65,respectively.The metasurface absorber is integrated with the vanadium oxide microbolometer,and the measured detector response spectrum is in good agreement with the absorption spectrum of the metasurface absorber.The peak responsivity of the two detectors is 1.0V/W and 1.46V/W,which are located at 6.0μm and 6.8μm,respectively.At the same time,the peak detection rates of the two detectors are 6.94×10^(5)cm·Hz^(1/2) W^(-1) and 9.95×10^(5)cm·Hz^(1/2) W^(-1),respectively,and the operating frequencies are 11Hz and 36Hz,respectively.Our work provides a new method for realizing large-array room-temperature multi-spectral polarization imaging detectors.