8-kW single-stage all-fiber Yb-doped fiber laser with a BPP of 0.50 mm-mrad

A 3.5-kW near-single-mode oscillating–amplifying integrated fiber laser

“…It can be found that the SRS intensity is about 23.61 dB lower than the signal light intensity at the maximum power and the 3-dB bandwidth is 5.62 nm. At present, the highest O–O efficiency of an all-fiber laser oscillator based on a common fiber is publicly reported as about 81% [ 20 ] , and the efficiency of this laser is obviously higher than that of a common fiber-based laser oscillator. The main reason is that there is no CLS between the oscillating section and the amplifying section, and the forward and backward pump light can be fully utilized.…”

“…In contrast, the fiber laser oscillator based on FP-fiber cavity has better anti-back reflected light ability, but the existence of the device insertion loss and output coupler grating loss makes a relative lower O-O efficiency. Currently, the highest output power of the all-fiber laser oscillator is 8 kW with an O-O efficiency of 81%, and the beam quality BPP (beam parameter product) value is 0.5 mm-mrad [20]. In order to increase the TMI threshold of fiber laser oscillator, K. Hejaz and others proposed a new laser structure and successfully increased the TMI threshold by ~26% (an increase of ~200 W) under the same conditions in 2018 [21].…”

“…In contrast, the fiber laser oscillator based on FP-fiber cavity has better anti-back-reflected light ability, but the existence of the device insertion loss and output coupler grating loss leads to a relative lower O–O efficiency. Currently, the highest output power of the all-fiber laser oscillator is 8 kW with an O–O efficiency of 81%, and the beam quality BPP (beam parameter product) value is 0.5 mm·mrad [ 20 ] .…”

Static and dynamic mode evolution in high-power distributed side-coupled cladding-pumped fiber amplifiers

“…acquiring high power visible light by frequency doubling [2], or realizing high precision industry materials processing [3]. With the rapid development of double clad fiber manufacture craft and high brightness laser diode pump sources, the output powers have soared up to multi-kilowatt [4][5][6], and a 10kW single mode fiber laser has been reported in 2009 [7]. However, due to the accumulated heat load at high average power, severe dynamic mode coupling -mode instabilityhas been triggered in the fiber lasers [8,9], which is the physical manifest of stimulated thermal Rayleigh scattering in fiber, and currently limits the power scaling and application area expanding of fiber laser systems [10][11][12].…”

Fabrication of 2 kW-Level Chirped and Tilted Fiber Bragg Gratings and Mitigating Stimulated Raman Scattering in Long-Distance Delivery of High-Power Fiber Laser

“…High-power fiber lasers have been widely used in lots of areas, such as industrial processing, medical treatment, material research, defense technology, and so on, due to their diffraction-limited beam quality, compactness, high efficiency, stability, and robustness [1][2][3]. In the past decade, thanks to the fast development of high-brightness laser diodes (LDs) and large-mode-area (LMA) fibers, the output power of fiber lasers has experienced an outstanding increase and promoted the rapid development of advanced manufacturing [4][5][6] of material processing and defense technology. However, SRS is still one of the primary limitations on further power scaling and the long-distance delivery of high-power fiber laser [7,8].…”