Fluoride-fiber-based side-pump coupler for high-power fiber lasers at 2.8  μm

Area of Science:

• Optics and Photonics
• Materials Science
• Laser Technology

Background:

• Development of efficient fiber laser systems is crucial for various applications.
• High-power fiber lasers often require robust and efficient pumping mechanisms.
• Fluoride glasses offer unique optical properties for mid-infrared applications.

Purpose of the Study:

• To fabricate and test a novel side-pump coupler utilizing fluoride fibers.
• To evaluate the coupling efficiency and high-power operation of the developed device.
• To demonstrate the potential for power scalability in fiber laser systems.

Main Methods:

• Fabrication of a side-pump coupler using fluoride fibers.
• Testing the device's coupling efficiency with incident pump power.
• Characterization of laser output stability and wavelength using an erbium-doped fiber.
• Evaluation of power scalability through testing with multiple devices.

Main Results:

• Achieved a coupling efficiency of 83% for the fluoride fiber side-pump coupler.
• Demonstrated high-power operation up to 83.5 W incident pump power.
• Obtained stable laser output of 15 W at approximately 2.8 μm wavelength for over 1 hour.
• Confirmed power scalability potential through tests with two coupled devices.

Conclusions:

• The developed fluoride-glass-fiber-based side-pump coupler is a novel and effective component for high-power fiber lasers.
• The device exhibits high coupling efficiency and stable operation at high pump powers.
• This technology offers a promising pathway for scalable mid-infrared fiber laser sources.