University of Shanghai for Science and Technology

Wenmei Hou

Yunbo Zhang

Xianbin Zhao

A laser interferometer system for measuring roll angle around the direction of linear displacement comprises a light source of a frequency stabilized input beam () with two linear orthogonally polarized components which may or may not be of the same frequency, a polarizing beam splitting prism, two quarter-wave retardation plates, a corner cube retroreflector, a prism assembly, attached to the mechanical apparatus whose roll angle of travel is to be measured, a wedge mirror assembly, a polarizer, a photoelectric detector, and a phase meter; the light source emits a frequency-stable incident beam and generates a stable electric reference signal; under the actions of the polarizing beam splitting prism, quarter-wave plate and corner cube retroreflector, the incident beam travels twice through and then reflected twice by the wedge mirror assembly, and finally exits from the polarizing beam splitting prism. The polarizer mixes the orthogonal components of the output beam and the photoelectric detector generates an electric signal and then the phase meter compares the phase difference of said electric measurement signal with said electric reference signal, then the roll angle of travel can be measured. The advantage of present invention is: the system has simple structure but with high measurement precision, it can be applied to the precision geometrical measurement and the establishment of precision benchmark metrology in wide high-tech fields such as military industry, aerospace engineering and digital controlled machine tools.

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Shanghai, China

Wenmei Hou