High-power continuous-wave Tm³⁺:Ho³⁺-codoped fiber laser operation from 2.1 µm to 2.2 µm

Area of Science:

• Laser Physics
• Materials Science
• Optical Engineering

Background:

• Thulium (Tm³⁺) and Holmium (Ho³⁺) co-doped fiber lasers are crucial for various applications requiring specific wavelengths.
• Investigating power scalability is essential for advancing laser technology and meeting industrial demands.

Purpose of the Study:

• To explore the power scalability of Tm³⁺:Ho³⁺ co-doped free-space single-oscillator fiber lasers.
• To achieve high-power laser emission in the 2.1 µm to 2.2 µm wavelength range.

Main Methods:

• Development of a tunable fiber laser source using a diffraction grating, covering a 200-nm range.
• Implementation of volume Bragg gratings (VBGs) for power scaling at specific wavelengths.
• Characterization of laser output power and slope efficiency.

Main Results:

• Stable high-power laser operation exceeding 10 W was achieved across a broad tunable range (1990 nm to 2190 nm).
• Power scaling using a VBG at 2.1 µm yielded 262 W output with a 49% slope efficiency.
• A record 77 W output power with a 29% slope efficiency was demonstrated at 2.2 µm using a VBG.

Conclusions:

• The Tm³⁺:Ho³⁺ co-doped fiber laser system exhibits excellent power scalability in the 2.1-2.2 µm range.
• The use of VBGs is effective for achieving high-power laser output at these wavelengths.
• This research paves the way for advanced applications requiring high-power, tunable laser sources.