为了能够更深入地理解等腰三角形亚波长光栅, 采用严格耦合波法对其进行了理论分析和研究, 得到了等腰三角形亚波长光栅数值模拟结果。分析了光栅周期、光入射角对等腰三角形亚波长光栅特性的影响, 并从内在磁场分布角度解释了等腰三角形亚波长光栅所表现出的高反射特性。结果表明, 不同光栅厚度的等腰三角形亚波长光栅会表现出不同的特性, 当光栅厚度在0.54μm~0.57μm之间, 等腰三角形亚波长光栅具有宽反射的反射带宽, 而当光栅厚度在0.58μm~0.66μm之间, 又会表现出导模共振特性。该研究能够为将来制备高性能等腰三角形亚波长光栅提供理论指导。

In order to understand the isosceles triangular subwavelength grating more deeply, the rigorous coupled-wave method was used forin-depth theoretical analysis and research, and the numerical simulation results of isosceles triangular subwavelength grating were obtained. The influence of grating period and incident angle on the characteristics of isosceles triangle subwavelength grating was analyzed, and the high reflection characteristic of isosceles triangle subwavelength grating was explained from the internal magnetic field distribution. The results show that isosceles triangular subwavelength gratings with different grating thicknesses exhibit different characteristics. When the grating thickness is between 0.54μm and 0.57μm, isosceles triangular subwavelength gratings have wide reflection bandwidth, while when the grating thickness is between 0.58μm and 0.66μm, guided mode resonance could be observed. The research can provide theoretical guidance for the preparation of high performance isosceles triangular subwavelength gratings in the future.