Boosting Backward Raman Amplification Performance Using an External Magnetic Field

This article presents a method of improving backward Raman amplification performance via the addition of an external static magnetic field longitudinal to the laser propagation direction. Our simulation results show that when the laser intensity is low, the output seed intensity can be increased by applying an external magnetic field and a right circularly polarized laser pulse. When the laser intensity is high, the magnetic field increases the self-phase modulation instability and decreases the output seed intensity. In such cases, a left circularly polarized laser pulse can suppress self-phase modulation instability and improve amplification performance. Dynamically adjusting the magnetic field, i.e., by using a double-pass scheme, can combine these two advantages and further improve the output seed intensity.