Volume Bragg grating stabilized spectrally narrow Tm fiber laser

Area of Science:

• Laser Physics
• Optical Engineering

Background:

• Thulium-doped large mode area (LMA) fiber lasers are crucial for various applications.
• Achieving stable, narrow-linewidth output from these lasers remains a challenge.

Purpose of the Study:

• To demonstrate a new method for spectrally limiting the output of LMA fiber lasers using a volume Bragg grating (VBG).
• To evaluate the performance of a VBG-stabilized Tm-doped LMA fiber laser and compare it to a laser using a dielectric mirror.

Main Methods:

• A Tm-doped LMA silica fiber laser was constructed.
• A volume Bragg grating (VBG) was employed to lock the laser output to a stable wavelength of 2,053.9 nm.
• The spectral width of the laser output was measured and compared to a laser using a dielectric mirror.

Main Results:

• The laser output was successfully locked to a stable wavelength of 2,053.9 nm with a spectral width <300 pm.
• The laser exhibited a modest output power of approximately 5W and a slope efficiency of 41%.
• Low VBG losses were implied by the performance characteristics.

Conclusions:

• Volume Bragg gratings (VBGs) provide an effective method for spectrally limiting Tm-doped LMA fiber lasers.
• This VBG-based approach is scalable to kilowatt powers, enabling new applications.
• The VBG method offers a viable alternative to dielectric mirrors for high-power fiber laser systems.