50 W low-noise single-frequency thulium-doped fiber amplifier at 1844 nm

Area of Science:

• Optics and Photonics
• Laser Technology

Background:

• High-power fiber lasers are crucial for advanced scientific and industrial applications.
• Existing laser systems often face limitations in power, spectral purity, and noise performance.

Purpose of the Study:

• To present a novel 50 W fiber laser amplifier architecture operating at 1844 nm.
• To demonstrate a robust design suitable for demanding applications like quantum computing.

Main Methods:

• A three-stage amplification architecture was employed, utilizing core-pumping in the initial stages and high-power cladding pumping for the final stage.
• Tunable output power up to 2 W was achieved with core-pumping at 1560 nm.
• An integrated spectral filter (circulator and fiber Bragg grating) and cladding pumping at 793 nm were used for power scaling and spectral control.

Main Results:

• Achieved over 50 W of output power at 1844 nm.
• Maintained an optical signal-to-noise ratio (OSNR) exceeding 60 dB.
• Demonstrated low Relative Intensity Noise (RIN) with RMS noise of 0.006% (1 kHz-10 MHz) and no Stimulated Brillouin Scattering (SBS).

Conclusions:

• The developed laser amplifier architecture meets critical requirements for narrowband emission, low noise, and reliability.
• The 50 W, 1844 nm laser is well-suited for advanced applications, including quantum computing and other scientific fields.
• The design showcases a viable path for high-power, high-quality laser sources.