Self-Calibration of a Large-Scale Variable-Line-Spacing Grating for an Absolute Optical Encoder by Differencing Spatially Shifted Phase Maps from a Fizeau Interferometer. - Xin Xiong; Chenguang Yin; Lue Quan; Ryo Sato; Hiraku Matsukuma; Yuki Shimizu; Hideaki Tamiya; Wei Gao 027 (Sensors, 2022)