论文标题
使用亚波长的金属二级结构增强红外阵列的每单位质量吸收
Enhanced absorption per unit mass for infrared arrays using subwavelength metal-dielectric structures
论文作者
论文摘要
红外阵列的吸收与质量比通过合并两个设计特征，比先前报道的结构大约1.33至7.33倍：首先，在像素周围空气差距中逃生场的耦合，以在内部的像素尺寸有效地创建更大的像素尺寸，然后在subishing Modeanance（gmr offiel gravever（gmr）中使用subercements（gmr）。双层Ti-Si3n4光栅通过薄Ti膜通过较厚的SI3N4膜通过薄Ti膜和振动语音子吸收的自由载体吸收的综合作用来实现宽带长波红外（LWIR，8至12 UM）的吸收。在GMR存在的情况下，即使使用低填充因子亚波长光栅细胞，这种宽带吸收也可以大大增强。此外，可以修改细胞的间距和设计，形成像素阵列结构，该结构将光线通过evaneScent Field耦合伴随着空气间隙。使用有限差时间域（FDTD）技术进行计算。观察到优化阵列的出色宽带吸收，在LWIR中获得90％的最大吸收，每个像素的平均每像素吸收量为3.45 $ \ times $ 10^{13} kgg^{ - 1}。
The absorption to mass ratio of the infrared arrays is enhanced to approximately 1.33 to 7.33 times larger than the previously reported structures by incorporating two design characteristics: first, the coupling of evanescent fields in the air gaps around pixels to create effectively larger pixel sizes, and, second, the use of guided mode resonance (GMR) within the subwavelength metal-dielectric gratings. The bilayer Ti-Si3N4 gratings achieve broadband long-wave infrared (LWIR, 8 to 12 um) absorption by the combined effects of free carrier absorption by the thin Ti films and vibrational phonon absorption by the thick Si3N4 films. In the presence of GMR, this broadband absorption can be enormously enhanced even with low fill factor subwavelength grating cells. Further, the spacing and design of the cells can be modified to form a pixel array structure that couples the light falling in the air gaps via evanescent field coupling. Calculations are performed using the finite difference time domain (FDTD) technique. Excellent broadband absorption is observed for the optimized arrays, yielding maximum absorption of 90 percent across the LWIR and an average absorption-per-unit-mass (absorption/mass) per pixel of 3.45$\times$10^{13} kg^{-1}.
