Narrowband random lasing in a Bismuth-doped active fiber.

Area of Science:

• Photonics and Laser Technology
• Materials Science

Background:

• Random fiber lasers utilizing Rayleigh scattering (RS) offer high-quality beams but typically require long passive fibers with Raman gain.
• Conventional active fibers are too short for significant RS feedback, limiting their use in random laser designs.

Purpose of the Study:

• To demonstrate the first realization of Rayleigh scattering-based random lasing in an active fiber.
• To explore the potential of a novel Bi-doped fiber for enhanced random laser performance.

Main Methods:

• Implementation of a novel Bi-doped fiber with extended amplification length and increased RS coefficient.
• Characterization of the laser output, including spectral properties and linewidth.

Main Results:

• Successful demonstration of RS-based random lasing in an active Bi-doped fiber.
• The Bi-fiber random laser operates at 1.42 μm, exhibiting a significantly narrower linewidth compared to conventional cavities of similar length.
• The developed laser aligns with theoretical predictions.

Conclusions:

• Active fiber random lasers based on RS feedback are feasible and offer unique advantages.
• Bi-doped fibers provide a versatile platform for tunable random lasers across a broad spectral range (1.15–1.78 μm).
• This technology holds significant potential for various laser applications requiring high-quality, tunable output.