布儒斯特角附近的透射光栅传输特性

 减小光栅表面的反射率以得到更高的衍射效率是目前光栅设计与制造中需要解决的重要问题之一。提出利用偏振光沿布儒斯特角入射时具有的特性来实现降低光栅表面反射率的方案，介绍了这种方案的物理模型，并利用严格耦合波分析法进行了模拟计算。计算结果显示，对入射光为TM偏振，波长0.35 μm，当光栅周期较长为2.80 μm时,以布儒斯特角入射的光波，它的表面反射被大大抑制；当光栅周期较短为0.21 μm时也有类似的结论，并且透射光的一级衍射效率极大值出现在刻槽深度为3.50 μm处附近，衍射效率大于95%。

Characteristcs of the tansmission grating under the Brewster angle

To reduce the reflection efficiency of the grating is the basic task during the design and fabricating process. Due to the speciality of the Brewster angle, the polarization light propagates at Brewster angle can reduce the reflection efficiency. In this paper, the physical model of this kind of scheme is introduced, and the strict coupling wave method is used to calculate the optical character of the transmission grating under the Brewster angle. The results show that if the angle of incidence is chose to Brewster angle when the grating period is 2.80μm(wavelength is 0.35 μm), the reflection efficiency of the grating is restrained. For the short cycle grating(period is 0.21 μm), the highest 1 order diffraction efficiency of the transmission beam can be at depth of 3.50 μm, and the peak value of the diffraction efficiency is more than 95%.