Laser Frequency Conversion in a Dynamic Plasma Grating

Laser-generated plasma gratings are dynamic optical elements for the manipulation of coherent light at high intensities, beyond the damage threshold of solid-stated based materials.They can be formed by a periodic ponderomotive potential generated by two identical counterpropagating Lasers. A fluid model is presented that allows to predict the peak value and formation time of the gratings, as well as kinetic simulations that show the existence of different regimes beyond the limitation of the fluid model[1, 2]. Combining fluid and kinetic results, general criteria for the peak value and life-time of the grating can be found. A novel application[3] of this transient plasma grating exploits its finite lifetime to affect the wave dispersion relation. As a result, different set-ups are identified that can result in laser frequency downshift or spectral splitting. The former can be used for Raman amplification in plasma and the latter for dual color x-ray generation by Thomson/Compton scattering.

References

[1] H. Peng, C. Riconda, M. Grech, J.-Q. Su, and S. Weber, Phys. Rev. E 100 061201(2019)

[2] H. Peng, C. Riconda, M. Grech, C. Zhou and S. Weber, Plasma Physics and Controlled Fusion 62 115015 (2020)

[3] H. Peng, C. Riconda, S.Weber, C. Zhou, S. C. Ruan, Phys. Rev. Applied 15 054053 (2021)