title: Green laser interferometric metrology system with sub-nanometer periodic nonlinearity.
abstract: This paper describes the design and realization of a heterodyne laser interferometer system that is applicable to metrology comparison. In this research, an iodine-stabilized Nd:YAG laser at 532 nm served as the light source. Two spatially separated beams with different offset frequencies are generated by two acousto-optic modulators to prevent any source mixing and polarization leakage. The interferometry components are integrated to a monolithic prism to reduce the difficulty of the light path adjustment and to guarantee the measuring accuracy. The experimental results show there is a sub-nanometer periodic nonlinearity, which mainly results from the ghost reflection. Placed in a vacuum chamber, the interferometer is applicable for measuring comparison using a piezo nanopositioner and a precision translation stage. Finally, a commercial interferometer is calibrated with the interferometer system.
authors.forename: Shijie
authors.initials: S
authors.lastname: Zhao
authors.forename: Haoyun
authors.initials: H
authors.lastname: Wei
authors.forename: Minhao
authors.initials: M
authors.lastname: Zhu
authors.forename: Yan
authors.initials: Y
authors.lastname: Li