A Cost-Effective Approach for Achieving Subwavelength THz Imaging Using Photoinduced Coded-Apertures on Mesa-Array Structures
A Cost-Effective Approach for Achieving Subwavelength THz Imaging Using Photoinduced Coded-Apertures on Mesa-Array Structures
复制标题
DOI：
10.1109/tthz.2022.3209535
复制
发表时间：
2022-11
影响因子：
3.2
通讯作者：
Yijing Deng;Yu Shi;Peizhao Li;P. Fay;Li-Jing Cheng;Lei Liu
中科院分区：
文献类型：
--
作者：
Yijing Deng;Yu Shi;Peizhao Li;P. Fay;Li-Jing Cheng;Lei Liu
报道了一种利用微机械台面阵列结构上的光致编码孔径实现高分辨率太赫兹(THz)成像的新方法。台面阵列结构被设计成具有亚波长电隔离台面，以产生用于太赫兹成像的高保真光特性。成功地制作了一个硅台面阵列原型结构并进行了测试。测量结果表明，在光强为11.7W/cm~2的情况下，在740~750 GHz的频率范围内，获得了22db的∼调制深度，与理论分析和全波模拟结果吻合较好。最初的成像实验首先使用像素(在不同区域)进行验证和性能评估。为了分辨亚波长特征，使用四倍像素数(256像素)进行了更高级的成像。结果，已经成功地展示了400μm的波长尺度空间分辨率，以及小到∼250μm(740GHz下的0.625λ)的亚波长分辨率已经被证明是潜在的。基于台面阵列的PI编码孔径成像是一种系统简单、成本低的实时高分辨率太赫兹成像方法。
A novel and cost-effective approach for high-resolution terahertz (THz) imaging using photoinduced (PI) coded-apertures on micromachined mesa-array structures is reported. The mesa-array structures are designed to have subwavelength electrically isolated mesas for generation of high-fidelity photopatterns for THz imaging. An Si mesa-array prototype structure was successfully fabricated and tested. Measurements show that a modulation depth of ∼22 dB was obtained in the frequency range of 740–750 GHz under a light intensity of 11.7 W/cm2, which agrees well with theoretical analysis and full-wave simulation. Initial imaging experiments were first performed using 64 pixels (over different areas) for validation and performance evaluation. More advanced imaging using quadrupled pixel number (256 pixels) was conducted in order to resolve subwavelength features. As a result, a wavelength-scale spatial resolution of 400 μm has been successfully demonstrated, and a subwavelength resolution as small as ∼250 μm (0.625λ at 740 GHz) has been shown to be potentially achievable. The proposed PI coded-aperture imaging using mesa arrays is promising for developing real-time high-resolution THz imaging with simple system and low cost.