连续太赫兹单像素亚波长成像系统

Research on continuous terahertz single-pixel subwavelength imaging system

摘要:

单像素成像是一种新颖的计算成像技术，借助于空间光调制，仅使用一个单像素探测器即可获取物体的图像。为克服太赫兹波段阵列探测器稀缺的难题，并在近场调制实现亚波长成像，提出一套基于光泵浦硅晶片的全光调制器的连续太赫兹单像素亚波长成像系统，可以实现λ/7.62的空间分辨力。对分辨力测试板的成像结果表明，对成像细节不特别关注时，可采用厚硅片获取大调制深度，并采用压缩重建算法抑制噪声，平滑输出图像；若要追求较高的成像空间分辨力，需采用薄硅片减小调制单元间的串扰，并采用关联重建算法，保留更多图像细节。本工作为太赫兹亚波长成像走向实际应用提供了一个新途径。

Abstract:

Single-pixel imaging is a novel computational imaging technique that uses only a single-pixel detector to acquire the image of an object with the help of spatial light modulation. In the terahertz band, to overcome the problem of scarcity of array detectors and realize sub-wavelength imaging in near-field modulation, a continuous terahertz single-pixel subwavelength imaging system is presented based on an optically pumped silicon wafer all optical modulator with a spatial resolution of λ/7.62. The imaging results on the resolution test chart show that when the imaging details are not of particular interest, thick silicon wafers can be employed to obtain large modulation depths, and the compressive reconstruction algorithm can be adopted to suppress noise and smooth the output images. To pursue higher imaging spatial resolution, thin silicon wafers are needed to reduce the crosstalk between modulation units, and the correlation reconstruction algorithm is employed to retain more image details. This study provides a concise reference for terahertz subwavelength imaging.