High power narrow-band fiber-based 
ASE source

Abstract

In this paper we describe a high power narrow-band amplified spontaneous emission (ASE) light source at 1030 nm center wavelength generated in an Yb-doped fiber-based experimental setup. By cutting a small region out of a broadband ASE spectrum using two fiber Bragg gratings a strongly constrained bandwidth of 12±2 pm (3.5±0.6 GHz) is formed. A two-stage high power fiber amplifier system is used to boost the output power up to 697 W with a measured beam quality of M2≤1.34. In an additional experiment we demonstrate a stimulated Brillouin scattering (SBS) suppression of at least 17 dB (theoretically predicted ~20 dB), which is only limited by the dynamic range of the measurement and not by the onset of SBS when using the described light source. The presented narrow-band ASE source could be of great interest for brightness scaling applications by beam combination, where SBS is known as a limiting factor.

Power scaling of narrowband high-power all-fiber superfluorescent fiber source to 187 kW

“…Jin et al [20] demonstrated a 228 W thulium-doped all-fiber narrowband SFS at 1968.1 nm with a FWHM linewidth of 0.19 nm. Schmidt et al [21] presented a 697 W narrowband space-structured SFS at 1030 nm with a bandwidth of 12 pm by using two fiber Bragg gratings (FBGs) as wavelength selection component. In this Letter, we report a narrowband all-fiber MOPA structured SFS with maximal output power of 1.87 kW.…”

Performance of kW class fiber amplifiers spanning a broad range of wavelengths: 1028~1100nm

“…To our understanding, so far the reported highest power achieved with narrow line-width from a fiber laser/amplifier at 1030 nm was no more than 700 W [6,7]. Although multi-kW CW output power centered at 1100 nm has been generated from fiber lasers recently [8,9], the line-widths are broad, more than 10 nm.…”

In-band pumping avenue based high power superfluorescent fiber source with record power and near-diffraction-limited beam quality

“…What is more, the presented high power SFSs in single-stage structure were often broadband and randomlypolarized [16][17][18][19] , while narrowband and polarization characteristics are required in practical applications [20,21] . Fortunately, employing master-oscillator-power-amplifier (MOPA) configuration can introduce a new horizon of high power SFS and leverage the high power SFS with special spectrum/polarization characteristics [22][23][24][25] and kilowatts operating power [26][27][28][29][30] . Besides, the output light of MOPAstructured SFS, in contrast to that of fiber MOPA seeded by standard resonant-cavity-based oscillator with self-pulsing effect, also has the advantages of high temporal stability [2,4] .…”