Highly Integrated Cladding Mode Stripper Array for Compact High-Power Industrial Fiber Laser

• Published in: Micromachines (Basel) 2022-12, Vol.13 (12), p.2226
• Main Authors: Liu, Yu, Wu, Wenjie, Zhao, Pengfei, Huang, Shan, Li, Yuwei, Li, Yue, Li, Min, Tao, Rumao, Lin, Honghuan, Wang, Jianjun
• Format: Article
• Language: English
• Subjects: Arrays; Cladding; cladding mode stripper; compact laser; Equipment and supplies; fiber laser; Fiber lasers; Fiber optics; Heat; Industrial applications; Industrial lasers; integrated device; Laser processing; Lasers; Miniaturization; optical fiber device; Strippers; Temperature; Weight reduction
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi13122226

A design integrating multiple cladding mode strippers used in fiber laser architectures into a single device is proposed. This approach can increase the compactness of fiber lasers, thus contributing to industrial laser processing applications. By offset-placing the most intense light-stripping parts, for instance, by inversing the laser injection directions or by displacing the beginning of etched sections, multiple cladding mode strippers bundled together into a single housing can have the hottest regions separated and can operate at full power simultaneously, with no evident cross-influence on each other. Two and three cladding-mode-stripper arrays have been implemented, and validation tests have been conducted with ~500-W cladding power being injected into each input port. For both arrayed devices, compared to the scenario in which only a single cladding mode stripper is working, no greater than a 2.1 °C temperature increment is generated when all components are operating concurrently, which demonstrates the effectiveness of the integration method. In this way, one half and two thirds of space/weight reduction can be realized, respectively, for the two and three cladding-mode-stripper arrays, which is meaningful, since cladding mode strippers are among the most bulky and hottest components in fiber lasers. Moreover, this integration provides a valuable reference for the miniaturization of other components, and thus, could contribute to the development fiber lasers with higher power-to-volume ratios, which would be more economical for industrial applications.