title: Note: Nonlinearity error compensated absolute planar position measurement using a two-dimensional phase-encoded binary grating.
abstract: This Note presents a new absolute planar position measurement method using a two-dimensional phase-encoded binary grating and a sub-division process where nonlinearity error is compensated inherently. Two orthogonally accumulated intensity profiles of the image of the binary grating are analyzed separately to obtain the absolute position values in each axis. The nonlinearity error caused by the non-ideal sinusoidal signals in the intensity profile is compensated by modifying the configuration of the absolute position binary code and shift-averaging the intensity profile. Using an experimental setup, we measured a circular trajectory of 100 nm radius, and compared the measurement result with that of a laser interferometer. Applying the proposed compensation method, the nonlinearity error was reduced to less than 15 nm.
authors.affiliation: Center for Length, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 305-340, South Korea.
authors.forename: Jong-Ahn
authors.initials: JA
authors.lastname: Kim
authors.forename: Jae Wan
authors.initials: JW
authors.lastname: Kim
authors.forename: Chu-Shik
authors.initials: CS
authors.lastname: Kang
authors.forename: Jonghan
authors.initials: J
authors.lastname: Jin
authors.forename: Tae Bong
authors.initials: TB
authors.lastname: Eom