Charca-Benavente Rafael, Kumar Rupesh, Rubio-Noriega Ruth, Clemente-Arenas Mark
Graduate School, Universidad Nacional de Ingeniería, Lima 15333, Peru.
Wireless Sensing and Imaging Laboratory & 6G Research Laboratory, SRM University AP, Amaravati 522502, India.
Materials (Basel). 2025 Jun 17;18(12):2847. doi: 10.3390/ma18122847.
In this work, we propose and analyze a thermally tunable metasurface based on indium antimonide (InSb), designed to operate in the terahertz (THz) frequency range. The metasurface exhibits dual functionalities: single-band perfect absorption and efficient polarization conversion, enabled by the temperature-dependent permittivity of InSb. At approximately 280 K, InSb transitions into a metallic state, enabling the metasurface to achieve near-unity absorptance (100%) at 0.408 THz under normal incidence, independent of polarization. Conversely, when InSb behaves as a dielectric at 200 K, the metasurface operates as an efficient polarization converter. By exploiting structural anisotropy, it achieves a polarization conversion ratio exceeding 85% over the frequency range from 0.56 to 0.93 THz, while maintaining stable performance for incident angles up to 45°. Parametric analyses show that the resonance frequency and absorption intensity can be effectively tuned by varying the InSb square size and the silica (SiO) layer thickness, achieving maximum absorptance at a SiO thickness of 16 μm. The proposed tunable metasurface offers significant potential for applications in THz sensing, imaging, filtering, and wavefront engineering.
在这项工作中，我们提出并分析了一种基于锑化铟（InSb）的热可调超表面，其设计用于在太赫兹（THz）频率范围内工作。该超表面具有双重功能：单波段完美吸收和高效偏振转换，这是由InSb随温度变化的介电常数实现的。在约280 K时，InSb转变为金属态，使超表面在垂直入射时于0.408 THz处实现接近100%的吸收率，且与偏振无关。相反，当InSb在200 K时表现为电介质时，超表面作为高效偏振转换器工作。通过利用结构各向异性，它在0.56至0.93 THz频率范围内实现了超过85%的偏振转换率，同时对于高达45°的入射角保持稳定性能。参数分析表明，通过改变InSb正方形尺寸和二氧化硅（SiO）层厚度，可以有效地调节共振频率和吸收强度，在SiO厚度为16μm时实现最大吸收率。所提出的可调超表面在太赫兹传感、成像、滤波和波前工程应用中具有巨大潜力。
