Frequency-stabilized Brillouin random fiber laser enabled by self-inscribed transient population grating

Area of Science:

• Photonics and Laser Technology
• Fiber Optics
• Quantum Optics

Background:

• Brillouin random fiber lasers (BRFLs) typically suffer from multimode instability and high relative intensity noise.
• Controlling mode competition in random lasers is crucial for practical applications.
• Erbium-doped fibers (EDFs) offer long-lifetime metastable states beneficial for laser dynamics.

Purpose of the Study:

• To propose and demonstrate a frequency-stabilized Brillouin random fiber laser (BRFL).
• To investigate the use of a self-inscribed transient population grating (TPG) for laser stabilization.
• To suppress random modes and reduce noise in BRFLs.

Main Methods:

• Formation of a transient population grating (TPG) in EDFs.
• Utilizing bidirectionally injected phonon-controlled random laser beams to create the TPG.
• Leveraging long-lifetime metastable ion states in EDFs to prolong laser dynamics.
• Theoretical and experimental validation of the TPG mechanism.

Main Results:

• Successful demonstration of a frequency-stabilized BRFL using a TPG.
• Suppression of significant random modes and reduction in relative intensity noise.
• Prolonged time dynamics of the stimulated Brillouin scattering (SBS) laser up to milliseconds.
• Establishment of a single dominating lasing mode due to reduced mode hopping.

Conclusions:

• The TPG method effectively stabilizes BRFLs, a first-time achievement.
• Long-lifetime metastable states in EDFs are key to achieving millisecond-level laser dynamics.
• This technique offers a promising pathway for low-noise, stable random fiber lasers.