Demonstration of laser pulse amplification by stimulated Brillouin scattering. (1st September 2014)

• Record Type: Journal Article
• Authors: Guillaume, E.; Humphrey, K.; Nakamura, H.; Trines, R. M. G. M.; Heathcote, R.; Galimberti, M.; Amano, Y.; Doria, D.; Hicks, G.; Higson, E.; Kar, S.; Sarri, G.; Skramic, M.; Swain, J.; Tang, K.; Weston, J.; Zak, P.; Alves, E. P.; Fonseca, R. A.; Fiúza, F.; Habara, H.; Tanaka, K. A.; Bingham, R.; Borghesi, M.; Najmudin, Z.; Silva, L. O.; Norreys, P. A.
• Is Part Of: High power laser science and engineering. Volume 2 (2014)
• Publication Date: 2014-09-01
• Subjects: laser–plasma interactions, -- optical pulse generation and compression, -- stimulated Brillouin and Raman scattering, -- ultra-fast optical processes; High power lasers -- Periodicals; 621.366
• DOI: 10.1017/hpl.2014.35
• Languages: English
• ISSNs: 2095-4719

Abstract

Abstract: The energy transfer by stimulated Brillouin backscatter from a long pump pulse (15 ps) to a short seed pulse (1 ps) has been investigated in a proof-of-principle demonstration experiment. The two pulses were both amplified in different beamlines of a Nd:glass laser system, had a central wavelength of 1054 nm and a spectral bandwidth of 2 nm, and crossed each other in an underdense plasma in a counter-propagating geometry, off-set by $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}10^\circ $ . It is shown that the energy transfer and the wavelength of the generated Brillouin peak depend on the plasma density, the intensity of the laser pulses, and the competition between two-plasmon decay and stimulated Raman scatter instabilities. The highest obtained energy transfer from pump to probe pulse is 2.5%, at a plasma density of $0.17 n_{cr}$, and this energy transfer increases significantly with plasma density. Therefore, our results suggest that much higher efficiencies can be obtained when higher densities (above $0.25 n_{cr}$ ) are used.