Optical phase conjugation in backward Raman amplification
Abstract
Compression of an intense laser pulse using backward Raman amplification (BRA) in plasma, followed by vacuum focusing to a small spot size, can produce unprecedented ultrarelativistic laser intensities. The plasma density inhomogeneity during BRA, however, causes laser phase and amplitude distortions, limiting the pulse focusability. To solve the issue of distortion, we investigate the use of optical phase conjugation as the seed pulse for BRA. We show that the phase conjugated laser pulses can retain focusability in the nonlinear pump depletion regime of BRA, but not so easily in the linear amplification regime. This somewhat counterintuitive result is because the nonlinear pump depletion regime features a shorter amplification distance, and hence less phase distortion due to wave–wave interaction, than the linear amplification regime.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 14, 2020
- Source ID
- 10.1364/ol.397321
Entities
People
- Kenan Qu
- Nathaniel Fisch
- Qing Jia
Organizations
- Air Force Office of Scientific Research
- National Nuclear Security Administration