Enhanced strong-coupling stimulated Brillouin amplification assisted by Raman amplification

Area of Science:

• Plasma Physics
• Laser-Plasma Interactions
• Nonlinear Optics

Background:

• Strong-coupling stimulated Brillouin scattering (SC-SBS) is a key process for laser amplification in plasma.
• Instabilities in pump lasers can limit SC-SBS efficiency and performance.
• Developing methods to enhance SC-SBS amplification is crucial for experimental applications.

Purpose of the Study:

• To investigate a hybrid amplification scheme combining Raman amplification and SC-SBS.
• To enhance the intensity and reduce the duration of amplified seed pulses.
• To suppress spontaneous instabilities in pump lasers during SC-SBS.

Main Methods:

• Utilizing a Raman pump laser for initial seed pulse amplification in homogeneous plasma.
• Employing a SC-SBS pump laser for subsequent amplification in inhomogeneous plasma.
• Conducting theoretical analysis using envelope coupling equations.
• Performing numerical simulations with Vlasov and 2D particle-in-cell (PIC) methods.

Main Results:

• Achieved higher intensity and shorter duration for the seed laser compared to pure SC-SBS.
• Maintained significant energy conversion efficiency.
• Demonstrated that SC-SBS amplification is seeded by the leading pulse from Raman amplification.
• Validated results across theoretical models and numerical simulations.

Conclusions:

• The combined Raman and SC-SBS amplification scheme effectively enhances laser intensity and pulse characteristics.
• This hybrid approach offers a viable strategy for improving SC-SBS performance in experimental settings.
• The findings provide a pathway for optimizing laser amplification in plasma-based experiments.