Compression of Terawatt Long-Wavelength Laser Pulses Through Backward Raman Amplification

We propose to compress a high-energy, picosecond long-wave infrared (LWIR) pulse in the plasma using backward Raman amplification (BRA). The apparatus is in a counter-propagating geometry that employs a 3 J, 3 ps CO
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laser pulse as the pump, and a microjoule, broadband femtosecond source as the seed. Simulations show that the amplified pulse can reach ~ 5 TW with a pulse duration of ~ 100 fs. Compared with earlier near-infrared BRA experiments, the proposed configuration uses a significantly shorter pump pulse duration, which may reduce limiting factors such as ion motions and Raman forward scattering. The experiment will be carried out at Accelerator Test Facility at Brookhaven National Laboratory.