| Abstract: | This research proposes a simple and practical method to make low-stray-light gratings, where the substrate shifts about a 1 mm distance in the direction parallel or perpendicular to the exposure interference fringes. When the substrate shifts, a reference grating next to the substrate is used to adjust in real time the phase of the exposure interference fringes relative to the substrate. Shifting eliminates the exposure defects and therefore decreases the stray light of gratings. Several gratings are successfully made by using this method, which have straighter grooves,smoother surfaces, and lower stray light than gratings made in conventional interference lithography. |
