High-precision and high-efficiency fabrication of blazed grating by ultrasonic-assisted ultraprecision planing

Blazed gratings are optical components typically employed in modern optical engineering. To realize high-precision and high-efficiency fabrication of blazed gratings on reliable materials, an ultrasonic-assisted ultraprecision planing (UAUP) method using a round-nose diamond tool under elliptical vibration mode is proposed in this paper. High-phosphorus electroless nickel-phosphorus plating was adopted as the grating blank. The generation mechanism of the blazed grating texture was studied, and the relationship between the processing parameters and blazed grating characteristic dimensions was established. Through a combination of simulation and experiment, the theoretical and experimental results of the morphologies and optical performances of the blazed gratings were systematically compared and analyzed. The results show that the blazed grating configuration is an envelope of the diamond tool profile under ultrasonic vibration; the UAUP method has an extremely high machining efficiency owing to the high vibration frequency; and the blazed gratings fabricated using smaller vibration amplitudes exhibit high machining quality, good shape consistency, and favorable optical performance, thus verifying the feasibility of the UAUP method.