Beam alignment based on two-dimensional power spectral density of a near-field image

• Published in: Optics express Vol. 25; no. 22; pp. 26591 - 26599
• Main Authors: Wang, Shenzhen, Yuan, Qiang, Zeng, Fa, Zhang, Xin, Zhao, Junpu, Li, Kehong, Zhang, Xiaolu, Xue, Qiao, Yang, Ying, Dai, Wanjun, Zhou, Wei, Wang, Yuanchen, Zheng, Kuixing, Su, Jingqin, Hu, Dongxia, Zhu, Qihua
• Format: Journal Article
• Language: English
• Published: United States 30.10.2017
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.25.026591

Beam alignment is crucial to high-power laser facilities and is used to adjust the laser beams quickly and accurately to meet stringent requirements of pointing and centering. In this paper, a novel alignment method is presented, which employs data processing of the two-dimensional power spectral density (2D-PSD) for a near-field image and resolves the beam pointing error relative to the spatial filter pinhole directly. Combining this with a near-field fiducial mark, the operation of beam alignment is achieved. It is experimentally demonstrated that this scheme realizes a far-field alignment precision of approximately 3% of the pinhole size. This scheme adopts only one near-field camera to construct the alignment system, which provides a simple, efficient, and low-cost way to align lasers.