title: Note: Periodic error measurement in heterodyne interferometers using a subpicometer accuracy Fabry-Perot interferometer.
abstract: Periodic error is the major problem that limits the accuracy of heterodyne interferometry. A traceable system for periodic error measurement is developed based on a nonlinearity free Fabry-Perot (F-P) interferometer. The displacement accuracy of the F-P interferometer is 0.49 pm at 80 ms averaging time, with the measurement results referenced to an optical frequency comb. Experimental comparison between the F-P interferometer and a commercial heterodyne interferometer is carried out and it shows that the first harmonic periodic error dominates in the commercial heterodyne interferometer with an error amplitude of 4.64 nm.
authors.affiliation: State Key Lab of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China.
authors.forename: Minhao
authors.initials: M
authors.lastname: Zhu
authors.affiliation: State Key Lab of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China.
authors.forename: Haoyun
authors.initials: H
authors.lastname: Wei
authors.affiliation: State Key Lab of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China.
authors.forename: Xuejian
authors.initials: X
authors.lastname: Wu
authors.affiliation: State Key Lab of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li