title: Measurement of M²-Curve for Asymmetric Beams by Self-Referencing Interferometer Wavefront Sensor.
abstract: For asymmetric laser beams, the values of beam quality factor M x 2 and M y 2 are inconsistent if one selects a different coordinate system or measures beam quality with different experimental conditionals, even when analyzing the same beam. To overcome this non-uniqueness, a new beam quality characterization method named as M²-curve is developed. The M²-curve not only contains the beam quality factor M x 2 and M y 2 in thex-direction andy-direction, respectively; but also introduces a curve of M x α 2 versus rotation angleαof coordinate axis. Moreover, we also present a real-time measurement method to demonstrate beam propagation factor M²-curve with a modified self-referencing Mach-Zehnder interferometer based-wavefront sensor (henceforth SRI-WFS). The feasibility of the proposed method is demonstrated with the theoretical analysis and experiment in multimode beams. The experimental results showed that the proposed measurement method is simple, fast, and a single-shot measurement procedure without movable parts.
authors.affiliation: College of Engineering, Huaqiao University, Quanzhou 362021, China. yongzhaodu@hqu.edu.cn.|Fujian Provincial Academic Engineering Research Centre in Industrial Intelligent Techniques and Systems, Huaqiao University, Quanzhou 362021, China. yongzhaodu@hqu.edu.cn.
authors.forename: Yongzhao
authors.initials: Y
authors.lastname: Du
keywords: beam quality M2-curve; fringe pattern analysis; laser beam characterization; self-referencing interferometer wavefront sensor