变栅距(VLS)衍射光栅具有自聚焦、像差校正等独特优点。VLS光栅要求的最小栅距变化量为亚纳米数量级,仅靠提高光栅刻划机的分度精度已很难实现,针对这一问题,提出了一种相位扫描方法用于光栅刻划机的变栅距分度控制,即通过对刻划机分度系统的干涉条纹进行微位移扫描来进行相位控制。实验结果表明,相位扫描方法达到了变栅距光栅所要求的亚纳米级的栅距变化精度。 Variable pitch (VLS) diffraction grating with self-focusing, aberration correction and other unique advantages. VLS grating required variation of the minimum pitch is sub-nanometer order of magnitude, only by improving the indexing accuracy of grating scoring machine has been difficult to achieve, in view of this problem, proposed a phase scanning method for grating grading machine Grating pitch control, that is, through the scoring machine indexing system interference fringes for micro-displacement scanning phase control. The experimental results show that the phase-scanning method achieves the sub-nanometer grating pitch variation accuracy required by the variable grating.