1kW fiber-coupled pump-module at 976nm with 50% efficiency

Area of Science:

• Optics and Photonics
• Laser Technology
• Materials Science

Background:

• High-power fiber lasers are crucial for industrial and scientific applications.
• Efficient and scalable pump sources are needed to achieve higher output powers.
• Current pump module technologies face limitations in power delivery and efficiency.

Purpose of the Study:

• To develop and characterize a novel fiber-coupled pump module for high-power fiber amplifiers.
• To demonstrate the scalability of these pump modules for multi-kilowatt laser systems.
• To assess the electrical-to-optical efficiency of the proposed pump module.

Main Methods:

• Design and fabrication of a fiber-coupled pump module emitting at 976nm.
• Characterization of the module's output power, beam quality, and spectral properties.
• Integration of multiple pump modules with a (6+1):1 multimode combiner.
• Testing of a Yb-doped fiber amplifier system powered by the developed modules.

Main Results:

• The pump module delivers over 1kW of mode-stripped power at 976nm from a 225µm, 0.22NA fiber.
• Electrical-to-optical efficiency reaches approximately 50% at 1kW output power.
• A 5-6kW single-mode Yb-doped fiber amplifier was successfully enabled using six pump modules.

Conclusions:

• The developed fiber-coupled pump module represents a significant advancement in high-power laser pumping.
• The modular design allows for scalable power delivery, enabling multi-kilowatt fiber amplifiers.
• This technology offers a promising solution for applications requiring high-power, efficient, and compact laser sources.