Research on beam bunching and deflection characteristics of low-power laser under the electromagnetic effect

• Published in: Measurement and control (London) Vol. 52; no. 5-6; pp. 379 - 386
• Main Authors: Zhang, Chi, Lu, Yonghua, Li, Jing, Wang, Rui
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.06.2019; Sage Publications Ltd; SAGE Publishing
• Subjects: Algorithms; Bunching; Coils; Correlation coefficients; Deflection; Electromagnetic fields; Faraday effect; Laser beams; Lasers; Linear polarization; Optical components; Polarized light; Rotation; beam deflection; electromagnetic cavity; low-power laser; beam bunching; Electromagnetic effect
• ISSN: 0020-2940; 2051-8730
• DOI: 10.1177/0020294019838575

The bunching and deflection characteristics of low-power laser beam were investigated under electromagnetic field. On the basis of the Faraday effect, the cylindrical electromagnetic cavity was designed and implemented in the experiments. Several types of the magneto-optical elements were placed in the electromagnetic cavity individually. In the test of the deflection characteristics of low-power laser, the rotating angle, the polarization plane of linearly polarized light which passed through electromagnetic cavity, was measured by polarization extinction. We focus on the relation between the coil current and the rotating angle. The experimental data show that when the coil current varies in the range of 0–5 A, the rotating angles changed from 0° to 24.1°. Then, a fitting formula about the coil current and the rotating angle was obtained from the experimental data using the least square algorithm. The analysis shows that the rotating angle is proportional to the excitation current and the correlation coefficient is more than 0.9995. In order to study the beam bunching characteristics of low-power laser, the area of the laser facula was measured after the low-power laser passed through the electromagnetic cavity. The experiment data show that the laser facula area changes in a small range and the experimental data meet 3σ criteria.