用空间光调制器模拟叉形光栅的方式产生高阶和分数阶涡旋光束，分离各阶涡旋光束并探究单级特性，探测其拓扑荷数以验证实验方法的正确性。设计了涡旋光束生成光路，编写了产生叉形光栅全息图的计算机程序，利用透射式空间光调制器模拟叉形光栅，以全息图的方式加载到空间光调制器上。调节参数改变全息光栅图样，得到拓扑荷数从1.0到100.0的整数阶与间隔为0.1的分数阶涡旋光束。利用孔径光阑分离出一级衍射，分析其特性并利用干涉法测量其拓扑荷数。实验发现，整数与分数阶光场分布与拓扑荷数为单调关系，拓扑荷数接近100时光束质量显著下降的特性，利用干涉法测得的拓扑荷数与计算全息图设置的参数完全相同。干涉测量结果验证了计算全息方法的正确性。该方法装置简易、参数可调，可为高阶和分数阶涡旋光的产生和应用提供一定的参考。

We report on subwavelength reflective gratings for hyperspectral applications operating in a very large spectral band (340–1040 nm). Our study concerns a blazed-binary grating having a period of 30 μm and composed of 2D subwavelength structures with size from 120 nm to 350 nm. We demonstrate the manufacturing of the gratings on 3″ wafers by two lithography technologies (e-beam and nanoimprint) followed by classical dry etching process. Optical measurements show that the subwavelength grating approach enables a broadband efficiency, polarization behaviour and wavefront quality improvement with respect to the requirements for the next generation of spectro-imagers for Earth observation missions. An outlook towards spherical substrate based on nanoimprint lithography is also reported with the results of mixed features replication (holes and pillars in the range of 160–330 nm) on a 540 mm concave substrate which demonstrate uniformity and accuracy capabilities over 3″ surface.

宽条形半导体激光器广泛应用于激光泵浦、激光加工等领域。针对宽条型半导体激光器输出光谱宽、调谐范围小的问题，采用衍射效率分别为28%和55%的反射式衍射光栅作为反馈元件构建了宽条形970 nm波长光栅外腔半导体激光器。研究了Littrow结构激光器参数对其性能（调谐范围、功率、阈值电流、线宽）的影响。实验结果表明，通过结构优化可得到窄线宽可调谐激光输出，适当地提高温度和使用较高衍射效率的光栅可增加激光器调谐范围，并且较高衍射效率的光栅可降低激光器的阈值电流。基于S偏振入射方式的光栅外腔激光器最大可实现27.87 nm的波长调谐范围，光谱线宽压窄至0.2 nm，输出功率可达1.11 W。