Enhanced Scattering of Laser Light by Optical Mixing in a Plasma

Abstract

The enhancement of the scattered signal due to the mixing of two optical beams in a plasma is observed. The two beams are produced in a dual-cavity organic-dye laser pumped by a Q-switched ruby laser. The presence of enhanced oscillations is demonstrated by a 50% increase in the intensity of the satellite in the scattered light spectrum of a third beam.

Experimental Studies of the Effects Observed During the Nonlinear Interaction of Two High-Power Radio Waves in a Magnetoplasma

“…This increase became smaller with increasing ∆f (with decreasing the HW frequency) and disappeared for ∆f ≈ 35 kHz corresponding to f HW ≈ 4f ce . A significant BUM Σ enhancement (about 4-5 dB) was also observed with respect to the BUM HW for ∆f ≈− (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) kHz (δf ≈ 40-50 kHz), when the HW frequency was higher than f DW . It is clear that such behavior of the BUM Σ intensity in comparison with the BUM DW and BUM HW , i.e., a 5-7-dB increase or a 10-15-dB decrease in the BUM Σ components related to the higher-or lower-frequency PW, respectively, cannot be explained within the framework of a variation in the total heating power and evidently results from the nonlinear interaction of two high-power radio waves in a magnetoplasma.…”

Laser-plasma interactions relevant to Inertial Confinement Fusion

“…[1.8]. Driving a resonant wave in this matter has been accomplished [25], and further experiments have…”

“…Until recently, most laser-driven fusion schemes viewed these laser-heated electrons as a nuisance which could pre-heat the fuel pellet and prevent a uniform compression. Laser-induced acceleration of electrons was first viewed in a positive light by the particle acceleration community [25], and today there is much research into high-gradient electron accelerators using laserplasma interactions.…”

Observation of resonant energy transfer between identical-frequency laser beams

“…Electron plasma waves can be driven in this manner, using two laser beams with a difference in frequency equal to the electron plasma frequency [2,4], and this technique has found applications in particle acceleration [5][6][7]. For beams of comparable frequency, resonance can be reached when (Ω,K) satisfies the dispersion relation (Ω=ω ia ,K=k ia ) for ion acoustic waves in a flowing plasma:…”