Improving the optical subdivision ability of a grating interferometer via double-row reverse blazed gratings

In this paper, a grating interferometer with higher optical subdivision ability is presented based on a reasonable configuration for blazed gratings. The proposed grating interferometer is characterized by the inverse side-by-side coupling of two blazed gratings. Because blazed grating has great diffractive efficiency at a specific diffraction order, this configuration allows for high optical subdivision by increasing diffraction times on the grating's surface. The operating principle of the proposed method is described in detail, and the corresponding experiment is carried out to evaluate its availability. The results show that 16 times optical subdivision can be realized, which means that we can achieve higher measurement resolution and accuracy for grating interferometers. It is relatively rare to employ blazed gratings as scale gratings to quantify displacement, and we anticipate that the construction of double-row reverse blazed gratings will establish the groundwork for further exploration of the grating interferometer's precision.