亚波长尺寸介质光栅作为一种特殊的周期性结构已经在滤波器、反射器、耦合器和传感器等方面取得了重要的进展，其中非均匀光栅具有极大的设计自由度，使其可以在太赫兹波段具有宽频带、高反射的特点，而且不同的光栅常数和填充因子会引起光栅光谱的频移，从而实现选频反射.文章设计并加工了一种非均匀硅基光栅，并利用反射式太赫兹时域光谱系统测试其反射特性并对其选频特征进行有限元分析.结果表明该非均匀硅基光栅太赫兹选频反射器不但具有频带宽、反射率高等优点，还具有结构简单、体积小、易于加工制作和工艺容差大等特征.

As a special periodic structure, sub wavelength gratings have made important progress in filters, reflectors, couplers, sensors and so on. Among them, the non-uniform grating has a great degree of design freedom, which enables it to have the characteristics of wide bandwidth and high reflectivity in terahertz range. Moreover, different grating constants and filling factors will lead to high selectivity in frequency spectrum, thus achieving tunable reflectors. In this paper, a non-uniform, silicon-based grating was designed and fabricated, and its reflection characteristics were measured by terahertz time-domain spectroscopy in reflection mode and calculated by finite element method. The results show that the non-uniform, high-selectivity, silicon-based grating not only has the advantages of wide frequency band and high reflectivity, but also has the characteristics of simple structure, small size, easy fabrication and large process tolerance.