论文标题
在等离子体中共线性激光脉冲的共振四光子散射
Resonant four-photon scattering of collinear laser pulses in plasma
论文作者
论文摘要
众所周知，共线平面激光脉冲的精确四光子共振是由等离子体电磁波的经典分散定律禁止的。我们在这里表明，任意小的相对论电子非线性产生的重新归一化消除了这一禁令。共线谐振四光子散射的激光频随激光强度增加。对于频率的激光脉冲比电子等离子体频率大得多，在仍然很小的相对论电子非线性下，移位也可能远大于等离子体频率，甚至几乎是输入激光频率的两倍。这可能会使频率和力量非常高的范围可调激光器。由于四光子散射不依赖于对等离子体均匀性非常敏感的Langmuir波，因此，这种激光器也能够在基于基于刺激的拉曼在血浆中的刺激的拉曼散射而在更大的血浆不均匀性下操作。
Exact four-photon resonance of collinear planar laser pulses is known to be prohibited by the classical dispersion law of electromagnetic waves in plasma. We show here that the renormalization produced by an arbitrarily small relativistic electron nonlinearity removes this prohibition. The laser frequency shifts in collinear resonant four-photon scattering increase with laser intensities. For laser pulses of frequencies much greater than the electron plasma frequency, the shifts can also be much greater than the plasma frequency and even nearly double the input laser frequency at still small relativistic electron nonlinearities. This may enable broad range tunable lasers of very high frequencies and powers. Since the four-photon scattering does not rely on the Langmuir wave, which is very sensitive to plasma homogeneity, such lasers would also be able to operate at much larger plasma inhomogeneities than lasers based on stimulated Raman scattering in plasma.
