High-beam-quality signal and pump combiner with large-mode-area fiber for high-power fiber laser and amplifier

Functional Fibers and Functional Fiber-Based Components for High-Power Lasers

“…A (6 + 1) × 1 SPC fabricated by Gu et al has been demonstrated with a remarkable power handling ability of over 3 kW. The launching efficiency for both signal and pumping beam reaches 98% and the measured M 2 of signal output is ~ 2.8 [162]. More recently, researchers released their self-made SPC utilized for backward pumping applications with a power handling of over 5 kW, the transmission efficiencies for signal laser and pumping light are 95.5% (together with negligible M 2 deterioration) and 98.2%, respectively [164].…”

“…Owing to the higher sensitivity to the injected NA, the working capacity of a single side-pumping combiner is limited to below 3 kW when it comes to pure LD pumping. Additionally, [161] (6 + 1) × 1 2.9 94.8%/null 2019 [162] (6 + 1) × 1 3.068 98.1%/> 97% 2021 [163,164] (6 + 1) × 1 5.05 98.2%/95.5% Accessed online [165] (18 + 1) × 1 2.5 > 95%/> 85% (36 + 1) × 1 2.5 > 93%/> 85% Accessed online [166] (6 + 1) × 1 2.4 Null/> 89% (18 + 1) × 1 3.6 (24 + 1) × 1 6.48 the tandem pumping strategy allows higher pumping injection with respect to LD sources. For example, a recording implementation has coupled a maximum pumping power of 5600 W at 1018 nm by using a (3 + 1) × 1 combiner [172].…”

2.02 kW and 4.7 GHz linewidth near-diffraction-limited all-fiber MOPA laser

“…23) Besides, using specially designed fiber is another practical approach to nonlinear effects suppression. 24) In 2016, depending on a gold-coated specialty active fiber with a 17 μm mode-field-diameter, a 3.1 kW and 12 GHz free-space coupling fiber amplifier with an M 2 factor of <1.15 was achieved. 25) In 2021, by adopting a doubletapered active fiber, a 4 kW all-fiber amplifier with an M 2 factor of 1.33 and a linewidth of 3.9 nm (∼1003.1 GHz) was developed.…”