Author Affiliations
Abstract
1 Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang, China
2 Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China
All-fiber coherent beam combiners based on the self-imaging effect can achieve a near-perfect single laser beam, which can provide a promising way to overcome the power limitation of a single-fiber laser. One of the key points is combining efficiency, which is determined by various mismatches during fabrication. A theoretical model has been built, and the mismatch error is analyzed numerically for the first time. The mismatch errors have been numerically studied with the beam quality and combining efficiency being chosen as the evaluation criteria. The tolerance of each mismatch error for causing 1% loss is calculated to guide the design of the beam combiners. The simulation results are consistent with the experimental results, which show that the mismatch error of the square-core fiber is the main cause of the efficiency loss. The results can provide useful guidance for the fabrication of all-fiber coherent beam combiners.
all-fiber coherent beam combination mismatch analysis self-imaging High Power Laser Science and Engineering
2024, 12(2): 02000e13
强激光与粒子束
2023, 35(4): 041005
强激光与粒子束
2022, 34(5): 051002
强激光与粒子束
2022, 34(2): 021002
Author Affiliations
Abstract
1 Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900, China
2 Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084, China
The self-imaging effect in a square core fiber has been investigated, and an integrated all-fiber combiner has been proposed based on a large mode area double clad fiber, which can be employed to construct high power coherent beam combining sources in the all-fiber format. The influence of various parameters on beam quality () and efficiency of the all-fiber coherent beam combiner has been studied numerically, which reveals that the near diffraction-limited laser beam can be achieved. A principle demonstration of the self-imaging effect has been carried out experimentally in a square core fiber, which proves the feasibility of beam combining with the square fiber, and that it is a promising way to develop high power coherent beam combination sources.
Photonics Research
2022, 10(2): 02000444
Author Affiliations
Abstract
Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900, China
We present a theoretical study of mode evolution in high-power distributed side-coupled cladding-pumped (DSCCP) fiber amplifiers. A semi-analytical model taking the side-pumping schemes, transverse mode competition, and stimulated thermal Rayleigh scattering into consideration has been built, which can model the static and dynamic mode evolution in high-power DSCCP fiber amplifiers. The mode evolution behavior has been investigated with variation of the fiber amplifier parameters, such as the pump power distribution, the length of the DSCCP fiber, the averaged coupling coefficient, the number of the pump cores and the arrangement of the pump cores. Interestingly, it revealed that static mode evolution induced by transverse mode competition is different from the dynamic evolution induced by stimulated thermal Rayleigh scattering. This shows that the high-order mode experiences a slightly higher gain in DSCCP fiber amplifiers, but the mode instability thresholds for DSCCP fiber amplifiers are higher than those for their end-coupled counterparts. By increasing the pump core number and reducing the averaged coupling coefficient, the mode instability threshold can be increased, which indicates that DSCCP fibers can provide additional mitigation strategies of dynamic mode instability.
distributed side-coupled cladding-pumped fiber high-power fiber lasers mode degradation mode instability High Power Laser Science and Engineering
2021, 9(4): 01000e58
强激光与粒子束
2021, 33(2): 021005
