This is achieved by a high numerical aperture (NA) lens axicon that utilizes spherical aberration to duplicate the performance of an axicon and to create an extended focal line.

• 该方法采用了高数值孔径的旋转三透镜，这种透镜利用球面透镜来复制旋转三棱镜的性能和产生一个延长焦线。