Abstract

High-power lasers, such as the Laser MegaJoule (LMJ), have to be phase modulated to avoid stimulated Brillouin scattering (SBS) that may strongly damage optics at the end of the laser chain. Current spectral broadening on LMJ is performed with a sinusoidal phase modulation. This pure sinusoidal phase modulation leads to inhomogeneous spectral power densities (SPD). Thus, for a same SBS power threshold, the sinusoidal phase-modulated spectrum has to be larger than the equivalent ideal SPD with isoenergetic peaks. We present in this paper a technique to generate energy-balanced Dirac peaks spectra thanks to nonsinusoidal phase modulations. Thus, we can build a narrower spectrum with a nonsinusoidal phase modulation that has the same SBS threshold as a sinusoidal phase modulation, and we show that FM-to-AM conversion can be strongly reduced, which is of great interest for LMJ laser performance, with reductions up to 40%.

© 2010 Optical Society of America

FM-to-AM conversion in high-power lasers

Steve Hocquet, Denis Penninckx, Edouard Bordenave, Claude Gouédard, and Yves Jaouën
Appl. Opt. 47(18) 3338-3349 (2008)

Random and pseudo-random phase modulations for FM-to-AM reduction in high power lasers

Martin Rabault, Jacques Luce, and Denis Penninckx
Appl. Opt. 57(31) 9287-9295 (2018)

Nonlinear FM-AM conversion due to stimulated Brillouin scattering

J. Luce, S. Montant, J. M. Sajer, C. Rouyer, D. Penninckx, J. Chou, J. Heebner, M. Rever, and J. M. Di Nicola
Opt. Express 27(5) 7354-7364 (2019)

Compensation of FM-to-AM conversion in high-power lasers

Huabao Cao, Xingqiang Lu, Linbo Li, Xianhua Yin, Weixin Ma, Jian Zhu, and Dianyuan Fan
Appl. Opt. 50(20) 3609-3614 (2011)

Impact of the Kerr effect on FM-to-AM conversion in high-power lasers

Denis Penninckx, Sébastien Montant, Jacques Luce, Édouard Bordenave, Élodie Boursier, and Claude Rouyer
Appl. Opt. 60(27) 8277-8285 (2021)