High-power cladding pumped Raman fiber amplifier with a record beam quality

Area of Science:

• Fiber optics
• Laser physics
• Nonlinear optics

Background:

• Raman amplifiers are crucial for generating specific wavelengths.
• Improving power and beam quality in fiber lasers is an ongoing challenge.
• Cladding-pumping offers advantages for high-power fiber laser systems.

Purpose of the Study:

• To present a high-power, high-brightness all-fiberized Raman amplifier.
• To demonstrate the effectiveness of a cladding-pumping scheme in a Raman amplifier.
• To achieve record output power and enhanced beam quality.

Main Methods:

• Utilizing a triple-clad passive fiber as the Raman gain medium.
• Implementing a cladding-pumping scheme for the Raman amplifier.
• Characterizing output power and beam quality (M²).

Main Results:

• Achieved a maximum output power of 762.6 W at 1130 nm.
• Demonstrated a record output power for cladding-pumped Raman amplifiers.
• Improved beam quality parameter (M²) from 6.12 to 2.24 at maximum power.
• Obtained the best beam quality (M²=1.9) at 267.2 W, outperforming existing configurations.

Conclusions:

• The developed all-fiberized Raman amplifier represents a significant advancement in high-power laser technology.
• Cladding-pumping is an effective strategy for achieving high power and brightness in Raman amplifiers.
• This work sets a new benchmark for beam quality in high-power Raman lasers.