Yb(3+)-ring-doped fiber for high-energy pulse amplification

Area of Science:

• Fiber optics
• Laser physics
• Materials science

Background:

• Traditional fiber amplifiers face limitations in energy storage due to amplified spontaneous emission.
• Optimizing gain medium geometry is crucial for improving amplifier performance.

Purpose of the Study:

• To demonstrate pulse amplification in a novel ring-doped fiber amplifier.
• To investigate the impact of ring doping on energy storage and amplified spontaneous emission.

Main Methods:

• Utilized a continuous-wave (cw) pumped Ytterbium (Yb3+)-doped fiber with a ring-shaped gain medium surrounding a single-mode core.
• Employed 540 mW of pump power at 1000 nm to amplify pulses.
• Measured extracted pulse energy at 1047 nm.

Main Results:

• Achieved 69 microJ of extracted pulse energy at 1047 nm, a record for a single-mode Yb3+-doped fiber amplifier.
• Demonstrated reduced gain and amplified spontaneous emission due to ring doping, enabling higher energy storage.
• Predicted potential for over 1 mJ pulse energies using diode bar cladding pumping.

Conclusions:

• Ring-doped fiber amplifiers represent a significant advancement in high-energy pulse generation.
• The demonstrated technique offers a pathway to overcome previous limitations in single-mode fiber amplifier energy storage.
• Future research directions include scaling to higher pulse energies through optimized pumping schemes.