Open AccessHeterodyne Wollaston laser encoder for measurement of in-plane displacement
Author(s) -
Hung-Lin Hsieh,
Wei Chen
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.008693
Subject(s) - optics , heterodyne (poetry) , interferometry , grating , laser , displacement (psychology) , physics , heterodyne detection , rotary encoder , encoder , optical path , computer science , acoustics , psychology , psychotherapist , operating system
This paper reports an innovative heterodyne Wollaston laser encoder with common-optical-path (COP) configuration for the measurement of in-plane displacement. The proposed technique combines the design concepts underlying heterodyne interferometry, grating interferometry, and COP configuration. According to the measurement principle, displacement information pertaining to a moving grating can be obtained from variations in the optical phase induced by the grating. Several experiments were performed to evaluate the feasibility and performance of the proposed heterodyne Wollaston laser encoder. Experiment results demonstrate that the proposed method is capable of sensing in-plane displacement to a resolution of 2 nm while maintaining the stability of the system against environmental disturbances.