Open AccessPump Side-scattering in Ultra-powerful Backward Raman Amplifiers
Author(s) -
A. A. Solodov,
V. M. Malkin,
Nathaniel J. Fisch
Publication year - 2004
Language(s) - English
Resource type - Reports
DOI - 10.2172/827678
Subject(s) - raman scattering , operability , raman spectroscopy , amplifier , raman amplification , thermal , optics , plane (geometry) , materials science , physics , computational physics , optoelectronics , computer science , mathematics , thermodynamics , software engineering , cmos , geometry
Extremely large laser power might be obtained by compressing laser pulses through backward Raman amplification (BRA) in plasmas. Premature Raman backscattering of a laser pump by plasma noise might be suppressed by an appropriate detuning of the Raman resonance, even as the desired amplification of the seed persists with a high efficiency. In this paper, we analyze side-scattering of laser pumps by plasma noise in backward Raman amplifiers. Though its growth rate is smaller than that of backscattering, the side-scattering can nevertheless be dangerous, because of a longer path of side-scattered pulses in plasmas and because of an angular dependence of the Raman resonance detuning. We show that side-scattering of laser pumps by plasma noise in BRA might be suppressed to a tolerable level at all angles by an appropriate combination of two detuning mechanisms associated with plasma density gradient and pump chirp