设计了一种新型同面相位补偿型等腰闪耀光栅。等腰设计保证了正负衍射级对称分布在光栅法线两侧;通过优化设计同面相位补偿槽的大小,可使衍射能量向中间级次转移,只保留两个衍射极大值方向,抑制0级和高衍射级能量分布,避免能量的浪费,而且降低了高衍射级次光线因刻线阻挡导致的散射噪声,解决了加工对准与多次衍射的难题。通过理论建模和计算机仿真,分析了与反面相位补偿等腰闪耀光栅的差异,绘制了典型的衍射光强分布图。另外,还探讨了这种新型等腰闪耀光栅的灰度掩模二元光学加工方法。

A new type of isosceles blazed grating with compensated phase on the obverse side (IBGCPOS) is designed. Isosceles design ensures the positive and negative diffractive orders distributing on the two sides of the grating normal symmetrically. By optimizing the size of the groove to observe phase compensation, the diffractive energy can be transferred to the middle orders. Two maximum diffractive directions are reserved. Energy distribution of zeroth order and higher orders diffraction is restrained, which can avoid energy wasting. Moreover,the problems of double-sided fabricating alignment and multiple-diffraction are solved. The theoretical model of diffraction intensity is founded and simulated by computer. The difference between IBGCPOS and the isosceles blazed grating with compensated phase on the inverse side (IBGCPIS) is analyzed. Typical distribution figures of diffraction intensity are given. In addition, the fabricating method with gray-scale mask for the new type grating is discussed.