Laser energies and powers, significantly much higher than available now through the most advanced chirped pulse amplifiers, might be achieved in much smaller devices. The working medium in such devices is plasma, capable of tolerating ultrahigh laser intensities within times shorter than it takes for filamentation instabilities to develop. The ultrafast amplification mechanism that outruns filamentation instabilities is the transient Raman backscattering of a laser pump in plasma. In principle, this mechanism is fast enough to reach nearly relativistic pumped pulse intensities, like 1017 W/cm2 for λ = 1 μm wavelength radiation. Such a nonfocused intensity would be 105 times higher than currently available. This mechanism also produces complete pump depletion. Many amplifiers with expensive and fragile meter-size gratings might then be replaced by a single amplifier comprised of a 1 cm size plasma layer. Raman instabilities of the pump to noise, as the pump traverses plasma layer towards the seed pulse, can be suppressed by detuning the resonance appropriately, even as the desired amplification process persists with high efficiency due to nonlinear resonance broadening. Moreover, since the peak intensity scales like 1/λ2, even much higher laser intensities might become feasible when appropriate x-ray pump lasers are developed.
|Number of pages
|Physics of Plasmas
|Published - May 2000
|41st Annual Meeting of the Division of Plasma Physics of the Ameircan Physical Society - Seattle, WA, United States
Duration: Nov 15 1999 → Nov 19 1999
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics