title: A dual-heterodyne laser interferometer for simultaneous measurement of linear and angular displacements.
abstract: Picometer laser interferometry is an essential tool for ultra-precision measurements in frontier scientific research and advanced manufacturing. In this paper, we present a dual-heterodyne laser interferometer for simultaneously measuring linear and angular displacements with resolutions of picometer and nanoradian, respectively. The phase measurement method is based on cross-correlation analysis and realized by a PXI-bus data acquisition system. By implementing a dual-heterodyne interferometer with a highly symmetric optical configuration, low frequency noises caused by the environmental fluctuations can be suppressed to very low levels via common-mode noise rejection. Experimental results for the dual-heterodyne interferometer configuration presented demonstrate that the noise levels of the linear and angular displacement measurements are approximately 1 pm/Hz(1/2) and 0.5 nrad/Hz(1/2) at 1 Hz.
authors.affiliation: MOE Key Laboratory of Fundamental Physical Quantities Measurements, The School of Physics, Huazhong University of Science and Technology, 1037 Luo Yu Road, Wuhan 430074, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Yan
authors.affiliation: MOE Key Laboratory of Fundamental Physical Quantities Measurements, The School of Physics, Huazhong University of Science and Technology, 1037 Luo Yu Road, Wuhan 430074, People's Republic of China.
authors.forename: Hui-Zong
authors.initials: HZ
authors.lastname: Duan
authors.affiliation: MOE Key Laboratory of Fundamental Physical Quantities Measurements, The School of Physics, Huazhong University of Science and Technology, 1037 Luo Yu Road, Wuhan 430074, People's Republic of China.
authors.forename: Lin-Tao
authors.initials: LT
authors.lastname: Li
authors.affiliation: MOE Key Laboratory of Fundamental Physical Quantities Measurements, The School of Physics, Huazhong University of Science and Technology, 1037 Luo Yu Road, Wuhan 430074, People's Republic of China.
authors.forename: Yu-Rong
authors.initials: YR
authors.lastname: Liang
authors.affiliation: MOE Key Laboratory of Fundamental Physical Quantities Measurements, The School of Physics, Huazhong University of Science and Technology, 1037 Luo Yu Road, Wuhan 430074, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Luo
authors.affiliation: MOE Key Laboratory of Fundamental Physical Quantities Measurements, The School of Physics, Huazhong University of Science and Technology, 1037 Luo Yu Road, Wuhan 430074, People's Republic of China.
authors.forename: Hsien-Chi
authors.initials: HC
authors.lastname: Yeh