Ruling of echelles and gratings with a diamond tool by the torque equilibrium method

Ruling of echelles and gratings by the torque equilibrium method is proposed to eliminate corrugated grating lines, rough blazed grating surfaces, and complex fabrication work such as step-by-step diamond tool deflection. A mathematical model of the torque equilibrium between the diamond tool and the metallic film during the ruling process is deduced to realize optimized diamond tool geometrical parameter design. Then, two echelles with identical areas of 80  mm×100  mm are separately ruled using the traditional deflecting tool ruling method and the proposed method, and the scatter light results for the two echelles are 9.6×10−4 and 3.1×10−4, respectively.