1.5kW linear polarized on PM fiber and 2kW on non-PM fiber narrow linewidth CW diffraction-limited fiber amplifier

Kilowatt-level, high brightness, narrow-linewidth polarization-maintained fiber amplifiers based on laser gain competition

“…22) Due to this the Brillouin gain in a PM fiber is higher than in a non-PM fiber, 23) power amplification and linewidth controlling in high-power, narrow-linewidth and PM all-fiberized amplifiers are more difficult. At present, beyond the kilowatt-level has been achieved with a spectral linewidth of >10 GHz 24,25) and a higher than 2.4 kW output power-level has been obtained with a linewidth of 60 GHz. 26) In this manuscript, we demonstrate that efficient SBS suppression can be fulfilled by using a laser gain competition and low repetition, high modulation depth sine RF phasemodulation signal.…”

“…At present, some effective SBS suppression methods have been proposed, such as using counter-propagation pumping, 5) short active fiber, 6,7) special designed active fiber, [8][9][10] imposing thermal and strains gradients, [11][12][13] and a employing phase modulation technique. 9,[14][15][16][17][18][19][20][21][22] By using the phase modulation technique, a higher than 2.5 kW output power has been achieved by some groups. 9,[14][15][16] However, the linewidth is normally broadened to be tens of GHz or many bulk space components are used in their structures.…”

“…9,[14][15][16][17][18][19][20][21][22] By using the phase modulation technique, a higher than 2.5 kW output power has been achieved by some groups. 9,[14][15][16] However, the linewidth is normally broadened to be tens of GHz or many bulk space components are used in their structures. In order to control the spectral linewidth for better time-coherence, laser gain competition and optimized phase modulation signals, such as pseudo random bit sequence and sinusoid radio frequency (RF), are proposed and utilized.…”

Recent Advances in Chirally-Coupled Core Fibers

“…In the past few years, people have devoted themselves to the power scaling of narrow linewidth (<100 GHz) output in all polarization-maintaining fiber lasers. In 2017, IPG Photonics developed a 1.5 kW polarization-maintaining narrow linewidth laser and a 2 kW non-polarization-maintaining narrow linewidth laser [11]. In 2018, they further increased the output power of the polarizationmaintaining fiber laser to 2 kW, and the output power of the non-polarization-maintaining fiber laser to 2.5 kW [12].…”

2.43 kW narrow linewidth linearly polarized all-fiber amplifier based on mode instability suppression

“…However, in commercial PM fibers, the polarization direction of the linear-polarized laser is parallel to the stress direction, so the bend loss of the HOM is reduced significantly due to photo-elastic effect [18]. This effect weakens the influence of the coil method on MI suppression, and results in the MI thresholds for the commercial PM fibers being lower than those of the non-PM fibers in the same coil package [12,19]. The comprehensive effect of these factors results in the power scaling of narrow linewidth linear polarized fiber laser being especially challenging, and the narrow linewidth linear polarized output power is still less than 2 kW [19][20][21].…”