Beam cleaning of an incoherent laser via plasma Raman amplification
We show that backward Raman amplification in plasma can efficiently compress a temporally incoherent pump laser into an intense coherent amplified seed pulse, provided that the correlation time of the pump is longer than the inverse plasma frequency. One analytical theory for Raman amplification using pump beams with different correlation functions is developed and compared to numerical calculations and particle-in-cell simulations. Since incoherence on scales shorter than the instability growth time suppresses spontaneous noise amplification, we point out a broad regime where quasi-coherent sources may be used as efficient low-noise Raman amplification pumps. As the amplified seed is coherent, Raman amplification provides an additional a beam-cleaning mechanism for removing incoherence. At near-infrared wavelengths, finite coherence times as short as 50 fs allow amplification with only minor losses in efficiency.
- Authors:
-
[1]
; [2]
; [1]
; [2]
- Princeton Univ., NJ (United States). Dept. of Mechanical and Aerospace Engineering
- Princeton Univ., NJ (United States). Dept. of Astrophysical Sciences
- Publication Date:
- Grant/Contract Number:
- 1506372; FA9550-15-1-0391; NA0002948
- Type:
- Accepted Manuscript
- Journal Name:
- Physics of Plasmas
- Additional Journal Information:
- Journal Volume: 24; Journal Issue: 10; Journal ID: ISSN 1070-664X
- Publisher:
- American Institute of Physics (AIP)
- Research Org:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Sponsoring Org:
- USDOE National Nuclear Security Administration (NNSA)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY
- OSTI Identifier:
- 1395338