1. Object azimuth measurement based on optical orbital angular momentum phase spectrum under tilted irradiation condition.
- Author
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Xu, Liyuan, Lin, Zizhuo, Ding, You, Liu, Zhengliang, Chen, Linlin, Ren, Yuan, and Liu, Tong
- Subjects
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ANGULAR momentum (Mechanics) , *AZIMUTH , *OPTICAL measurements , *OPTICAL remote sensing , *LAGUERRE-Gaussian beams , *OPTICAL vortices , *IRRADIATION - Abstract
• An object azimuth measurement method based on OAM phase spectrum under tilted irradiation condition is proposed. • We analyze the relationship between the measurement error caused by the beam oblique irradiation and the angle of tilt and propose an error compensation method. After error compensation, the average error is kept below 0.73° at all tilt angles. • A four-step phase-shifting method is used to measure the helical phase of a vortex beam. In optical remote sensing, a beam carrying orbital angular momentum can be used to identify the azimuth of an object. However, most of the studies reported currently require the beam to be illuminated vertically to the surface of the object, and the general case of tilted irradiation for the beam has not been fully discussed. In this paper, an object azimuth measurement method based on orbital angular momentum phase spectrum under tilted irradiation condition is proposed. We analyze the relationship between the measurement error caused by the beam oblique irradiation and the angle of tilt and propose an error compensation method. In the experiment, the orbital angular momentum phase spectrum of the Laguerre-Gaussian beam is obtained by a four-step phase-shifting method, and the error caused by tilt modulation is measured. After implementing the error compensation scheme, the maximum absolute error in azimuth measurement under tilted irradiation conditions is maintained within 2.15°. Across all tilt angles, the average absolute error remains below 0.73°. The method proposed in this paper has a certain reference value for expanding the practical application of orbital angular momentum beams in the field of remote sensing. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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