Texture morphology and optical performance control of blazed gratings via ultrasonic-assisted ultraprecision planing

Blazed gratings are essential optical components for diffraction-based applications. To enable high-precision and high-efficiency fabrication of blazed gratings, an ultrasonic-assisted ultraprecision planing (UAUP) method employing elliptical vibration with extensively tunable parameters was proposed. This paper systematically investigates the effects of different UAUP processing parameters on the morphology and optical performance of blazed gratings through experiment, simulation, and characterization. The results demonstrate that the vertex shift ratio (r) critically determines the grating morphology and optical performance, which can be controlled by the tool clearance angle (α_o), vibration amplitudes (A_y and A_z), and nominal cutting speed (v). Utilizing smaller α_o, smaller A_y/A_z, and larger v facilitates better optical performance, and the maximum diffraction efficiency reaches 67.30%, meeting the standard for commercial applications. The high-precision morphology and excellent optical performance attained with optimized processing parameters validate the feasibility of UAUP for fabricating high-quality, complex, and controllable blazed grating textures.