Plasma optics for intense laser amplification

Laser amplification through plasma-based techniques might overcome the thermal damage limit of conventional materials, thereby enabling the next generation of laser intensities. The leading plasma-based method is Raman compression: a long laser pump decays into a plasma wave and a counterpropagating short laser seed pulse, which, capturing the pump energy, reaches extreme intensities. The technological requirements on the seed are severe: it must be very sharp and matched properly in frequency. To sharpen the seed pulse, we propose a laser-controlled, super-fast plasma shutter technique, analogous to electromagnetically induced transparency (EIT) in atoms. We further show that the laser seed may even be replaced by a stationary plasma wave seed. In the important pump-depletion regime, the plasma-wave initiated output pulse approaches the self-similar attractor solution for the corresponding laser seed, with the frequency match automatic. These techniques also work with partially coherent pumps. Actually, a partially coherent pump can even advantageously suppress the noise-seeded spontaneous Raman amplification which is responsible for premature pump depletion.