An imaging grating diffractometer for traceable calibration of grating pitch in the range 20 μm to 350 nm

[摘要] This work describes the development of a grating diffratometer to provide traceable calibration of grating pitch in range 20 μm to 350 nm. The approach is based on the Littrow configuration in which a laser beam is directed onto the grating which is mounted on a rotary table and can be turned so that each selected diffraction order is retro-reflected in the laser incidence direction. A beamsplitter and a lens direct the reflected diffraction order to form a small image spot on a CCD camera and the spot centering is used to adjust to rotation angle, thereby giving the diffraction angle. Knowing the diffraction angle for several orders and the wavelength of the laser, the average grating pitch can be determined to an uncertainty the order of 14 pm.

[发布机构] Dimensional Metrology Laboratory (Lamed), Mechanical Metrology Division (Dimec), Direct. of Scientific and Industrial Metrology (Dimci), National Institute of Metrology, Quality and Technology (Inmetro), Av. Nossa Senhora das Graças, 50, Xerém, RJ, Duque de Caxias; 25250-020, Brazil^1;Canadian Dimensional Metrology, Ottawa, Canada^2

[效力级别] 力学 [学科分类] 力学，机械学

[关键词] Diffraction angle;Diffraction orders;Grating pitch;Littrow configuration;Rotary tables;Rotation angles;Traceable calibration