Imaging with a rectangular phase grating applied to displacement metrology.
We achieved displacement metrology with a high-amplitude signal by using a rectangular phase grating as the pupil in a grating imaging system. The imaging phenomenon with a pupil transmission grating that has a bilevel profile with a 50% duty ratio is discussed on the basis of the optical transfer function. By optimizing the imaging condition, we obtained high-contrast images with high light power under a magnified or demagnified imaging system. The amplitude of the signal in the displacement measurement was four times higher than that of the conventional grating imaging system with amplitude gratings.
Nayoga Works, Mitsubishi Electric Corporation, Nayoga 461-8670, Japan. Omura.Yoichi@ab.MitsubishiElectric.co.jp
Yoichi
Y
Ohmura
Toru
T
Oka
Toshiro
T
Nakashima
Kazuhiro
K
Hane