Industrial 6 kW high-stability single-stage all-fiber laser oscillator based on conventional large mode area ytterbium-doped fiber

Abstract

We have demonstrated an industrial 6 kW single-stage end-pumped all-fiber laser oscillator based on a conventional large mode area ytterbium-doped fiber (YDF) with 30 μm core diameter and 600 μm inner-cladding diameter. As a result, the fiber oscillator achieved a maximum output power of 6.07 kW at a central wavelength of ∼1080 nm with a slope efficiency of ∼65.8%. The power of Raman Stoke light was 21.6 dB smaller than the signal light at the output power of 6.07 kW. For industrial application, the stimulated Raman scattering effect was further suppressed by employing a 50 μm-core delivery fiber, and no sign of dynamic transverse mode instability comes into view during the whole experiment. The power stability measurement at ∼6 kW operation was carried out for continuous 2 h, and the power fluctuation was within 0.31%. To the best of our knowledge, this is the first detailed demonstration of industrial 6 kW high-stability single-stage all-fiber laser oscillator based on conventional YDF. The results provide a significant guidance for the construction of more than 6 kW output power single-stage end-pumped all-fiber laser systems.

Power Scaling of CW Crystalline OPOs and Raman Lasers

“…OPOs rely on parametric amplification to generate two photons-namely signal and idler, with energies lower than the pump photons incident on the nonlinear crystal placed in a resonator [2,18,19]. The limitations of these oscillators is the requirement of a highly intense, low-divergent, and polarized pump field [18,20].…”

“…OPOs rely on parametric amplification to generate two photons-namely signal and idler, with energies lower than the pump photons incident on the nonlinear crystal placed in a resonator [2,18,19]. The limitations of these oscillators is the requirement of a highly intense, low-divergent, and polarized pump field [18,20]. Raman lasers, on the other hand, rely on stimulated scattering in which pump photons interact with optical phonons to generate Stokes photons with energy lower than the pump.…”

Experimental Study on Transverse Mode Instability Characteristics of Few-Mode Fiber Laser Amplifier Under Different Bending Conditions

“…IGH-power fiber lasers have been widely used in industrial manufacture, biomedical technology, fundamental research and other fields during past years owing to their excellent beam quality, flexible operation, convenient thermal management and other advantages [1][2][3][4][5]. Benefiting from the progress of high brightness pump sources and fiber devices manufacture technology, the power scaling of fiber lasers has been greatly improved [6][7][8]. However, the output power to a single fiber has limit due to launched pump power, nonlinear effects, optical damage and TMI [9][10][11][12].…”

Fiber Fuse Simulation in Double-Clad Fibers for High-Power Fiber Lasers

“…Typical LMA fibers used in the CW laser operation have core diameters of 20-40 µm and an NA of < 0.09 [23][24][25][26][27]. High output power of > 200 W in the CW laser operation has been reported using cladding-pumped Yb-doped and/or Nd+Yb-doped LMA fibers [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. On the other hand, it is extremely challenging to increase the fiber core size while retaining the excellent beam quality because fibers with large core size allow propagation of several transversal modes, except for the fundamental mode (FM).…”