High-Power Fiber Laser Systems and Applications

High-power fibre laser systems have matured into a versatile platform for scientific, industrial and defence applications. These systems typically employ rare-earth-doped fibres, such as ytterbium-doped silica, configured in large-mode-area designs and pumped in cladding architectures to achieve kilowatt-class output. Critical obstacles to power scaling include nonlinear optical phenomena—such as stimulated Brillouin scattering (SBS) and stimulated Raman scattering—as well as transverse mode instability (TMI) driven by thermally induced refractive index fluctuations. Advances in waveguide engineering, spectral broadening techniques and multimode excitation strategies have substantially raised thresholds for these deleterious effects. Innovative approaches such as pseudo-random phase modulation, higher-order mode delocalisation and wavefront shaping enable simultaneous suppression of SBS and TMI while preserving near-diffraction-limited beam quality. The global impact of these developments spans precision materials processing, directed-energy systems, remote sensing, lidar, gravitational-wave observatories and medical surgery, underscoring the transformative potential of further power scaling in fibre laser technology.

Research from Nature Portfolio

Recent studies have demonstrated wavefront shaping in highly multimode fibres to suppress SBS by broadening the Brillouin spectrum under multimode excitation, raising the power threshold by an order of magnitude while controlling beam profile. This approach applies to both continuous-wave and pulsed regimes, enabling power scaling beyond conventional single-mode limits and paving the way for enhanced performance in directed energy, remote sensing and precision measurement.

High-Power Fiber Laser Systems and Applications publication trend

The graph below shows the total number of articles in high-power fiber laser systems and applications across all publications each year (not limited to Nature Index journals).

Technical terms

Stimulated Brillouin Scattering (SBS): A nonlinear interaction between light and acoustic phonons in a fibre that back-scatters and depletes the optical signal, limiting power scaling.

Transverse Mode Instability (TMI): A thermally driven transfer of energy among transverse modes in high-power fibre amplifiers that degrades beam quality above a power threshold.

Large Mode Area (LMA) Fibre: A fibre design with an increased core diameter to reduce optical intensity and suppress nonlinear effects, facilitating higher power operation.

Wavefront Shaping: A technique to control the spatial phase of input light across multiple modes, enabling suppression of nonlinear scattering and beam profile control.

Beam Quality (M²): A metric of how closely a laser beam approaches the ideal diffraction-limited Gaussian profile, with M² = 1 denoting perfect quality.

References

1. Mitigating stimulated Brillouin scattering in multimode fibers with focused output via wavefront shaping. Nature Communications (2023).
2. Single-mode regenerative amplification in multimode fiber.. Optica (2023).
3. Theory of transverse mode instability in fiber amplifiers with multimode excitations. APL Photonics (2024).
4. Single mode 4.3 kW output power from a diode-pumped Yb-doped fiber amplifier.. Optics Express (2017).
5. Pseudo-random binary sequence phase modulation for narrow linewidth, kilowatt, monolithic fiber amplifiers. Optics Express (2014).
6. Yb-doped large-pitch fibres: effective single-mode operation based on higher-order mode delocalisation. Light: Science & Applications (2012).