LD-cladding-pumped 50 pm linewidth Tm 3+ -doped silica fiber laser

Area of Science:

• Laser Physics
• Materials Science
• Optical Engineering

Background:

• Thulium (Tm3+)-doped fiber lasers are crucial for generating light in the 2-micron wavelength range.
• Achieving narrow linewidth and high output power simultaneously presents a significant challenge in fiber laser development.

Purpose of the Study:

• To develop a Tm3+-doped fiber laser source with a narrow linewidth and significant output power.
• To investigate the spectral characteristics and optimize the output of the fiber laser.

Main Methods:

• Utilized an 82 cm long Tm3+-doped multimode-core fiber.
• Employed a 792 nm laser diode for cladding pumping.
• Constructed a fiber laser cavity with a high-reflective dichroic mirror and a fiber Bragg grating (FBG) output coupler.
• Measured the transmission spectrum of the multimode FBG and the output laser spectrum.

Main Results:

• Achieved a continuous wave (cw) laser output power of up to 2.4 W at 1936.4 nm.
• Obtained a narrow laser linewidth of 50 pm.
• Demonstrated the ability to transition from a multipeak to a single-peak laser spectrum by adjusting cavity parameters.

Conclusions:

• The Tm3+-doped fiber laser system is capable of producing high-power, narrow-linewidth output.
• Cavity design and optimization, specifically the adjustment of the distance between the dichroic mirror and the fiber end, are critical for achieving single-mode operation.
• This laser source shows promise for applications requiring precise and powerful light in the 2-micron region.