Direct-diode-pumped 10-W-level all-fiber laser at 3003 nm.

Area of Science:

• Laser Physics
• Optical Engineering
• Materials Science

Background:

• High-power fiber lasers operating at mid-infrared wavelengths (around 3 μm) are crucial for various applications.
• Achieving high output power levels from fiber lasers at these wavelengths, particularly using direct laser-diode (LD) pumping, presents significant challenges.

Purpose of the Study:

• To demonstrate a high-power all-fiber laser system operating at 3003 nm.
• To achieve a 10-W output power level using direct LD pumping.
• To investigate the factors limiting laser performance at this gain edge.

Main Methods:

• Fabrication of a laser resonator using an 8-m heavily Er3+-doped fluoride fiber.
• Inscribing fiber Bragg gratings (FBGs) directly into the doped fiber using the femtosecond laser direct writing technique.
• Implementation of an independent temperature-control strategy for precise spectral alignment of FBGs.
• Utilizing numerical simulations to analyze power saturation and roll-off phenomena.

Main Results:

• Achieved a maximum output power of 10.26 W at 3003 nm, the first reported 10-W level output via direct LD pumping.
• Demonstrated the effectiveness of precise temperature control for optimizing laser performance.
• Numerical simulations elucidated the impact of FBG thermal instability on power saturation and roll-off at high pump levels.

Conclusions:

• The study successfully demonstrated a compact and robust high-power all-fiber laser at 3.0 μm.
• Findings provide critical insights into overcoming limitations for high-power mid-infrared fiber laser development.
• The developed laser system and understanding of FBG thermal effects pave the way for future advancements in this field.