Highly efficient mid-infrared dysprosium fiber laser.

Area of Science:

• Laser Physics and Photonics
• Materials Science
• Quantum Electronics

Background:

• Development of efficient and scalable pump schemes is crucial for advancing fiber laser technology.
• Mid-infrared (3 μm) fiber lasers have applications in spectroscopy, medical diagnostics, and materials processing.
• Previous pumping methods for Dy³⁺ lasers faced limitations in efficiency and scalability.

Purpose of the Study:

• To present a new, highly efficient, and power-scalable pump scheme for 3 μm class fiber lasers.
• To demonstrate direct excitation of the Dy³⁺ upper laser level using a 2.8 μm Er³⁺-doped fiber laser.
• To achieve high output power and efficiency at specific mid-infrared wavelengths.

Main Methods:

• Utilized a free-running 2.8 μm emission from an Er³⁺-doped fluoride fiber laser.
• Employed direct excitation of the H_13/26→H_15/26 transition in Dy³⁺ ions.
• Used comparatively long lengths of Dy³⁺-doped fluoride fiber for laser operation.

Main Results:

• Achieved a record slope efficiency of 51% for output at 3.04 μm.
• Demonstrated laser output at 3.04 μm via direct pumping.
• Measured a maximum emission wavelength of 3.26 μm using Dy³⁺-doped fluoride fiber.

Conclusions:

• The presented pump scheme is highly efficient and power scalable for 3 μm fiber lasers.
• Direct excitation offers a viable pathway for high-performance Dy³⁺-doped fiber lasers.
• This technique opens possibilities for generating laser light at various mid-infrared wavelengths.