title: Measurement method for optical retardation based on the phase difference effect of laser feedback fringes.
abstract: We present a measurement method for optical phase retardation, which utilizes a phase-difference phenomenon of the feedback fringes in orthogonally polarized directions of a laser with anisotropic weak feedback. This phase difference is dominated by the measured retardation. The measurement principles are given based on the 3-mirror cavity model, and experiments are conducted with quartz waveplates (WPs). A measurement range 0°-180° is achieved, the uncertainty is theoretically better than 0.5°, and the measurement precision can be improved further. This method does not require researchers to know beforehand the principal axes directions of the WPs, and has better anti-disturbance ability than the previous method based on laser feedback.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.forename: Shijie
authors.initials: S
authors.lastname: Zhao
authors.forename: Yidong
authors.initials: Y
authors.lastname: Tan
authors.forename: Shulian
authors.initials: S
authors.lastname: Zhang