2.C Raman Scattering of High-Power Lasers in Air
نویسندگان
چکیده
Inertial-confinement lascr fusion requires propagation of high-intensity, pulseshaped IR and UV laser beams through long air paths. Such beams are subject to losses and decreased beam quality because of stimulated rotational Raman scattering (SRRS) in the atmosphere. With short pulses, it is necessary to use transient Raman theory to include buildup and relaxation of the mcdium. Imperfect beam quality can lead to intensity hot spots that change the effective threshold for Raman scattering. A detailed analysis of energy conversion and beamquality necessitates a four-dimensional (4-D) treatment of the laser pump, the Stokes beam, and the air path. The SRRS model includes laser pulse shape, medium excitation and relaxation, and spontaneous scattering as a quantum initiation of the Stokes field.
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