提出通过光栅条纹相位的精密测量，获取光栅高精度位移信息的方法。具体方法是对光栅图像采用多码道设计，用CCD二维图像传感器获取测量段光栅图像多码道信息。对最低码道图形的周期函数序列进行傅里叶变换、基频滤波和逆傅里叶变换获得光栅截断相位分布，其余码道信息提供相位展开的级次，以此获得测量段光栅的绝对相位分布。用光刻的手段制作了实用的绝对编码光栅，基元码道的尺寸是：27.36 μm用于明条纹，27.36 μm用于暗条纹，最小基元码道空间周期为54.72 μm,光栅长度为14008.32 μm。在步长近似3 μm的位移测试中，与比对的标准仪器记录值比较，标准偏差为0.2057 μm，精度在亚微米量级。重复性实验表明，位置测试的稳定性为0.09 μm （标准差），得到600倍以上细分的分辨力。

A phase subdivision of absolute coding is proposed to enhance the resolution of absolute coding grating in displacement measurement . The used grating consists of multiple code channel grating. CCD image sensor acquires information of multiple code channel in measurement section. The absolute phase distribution in measurement section is obtained by Fourier transform, filtering, inverse Fourier transform, and phase unwrapping. Practical absolute coding grating is fabricated by lithography. The size of minimum code pattern is 27.36 μm for light and dark fringe. Space period of benchmark code sequence pattern is 54.72 μm, and the length of grating is 14008.32 μm. A large number of displacement tests are carried out. In the displacement test of step length approximate 3 μm, compared with the record value of standard equipment, the standard deviation is 0.2057 μm. The precision reaches sub-micron level. The stability tests demonstrate that the resolution of 600 times of subdivisions on minimum code pattern is gotten.