If another photon strikes one of these high-energy electrons, the electron releases two photons that travel together at the same wavelength.

VOA: special.2010.09.01

So this means that we can go directly from the energy between two levels to the frequency of the photon that's emitted when you go between those levels.

这意味着我们可以直接,从两个能级的能量得到它们之间,跃迁发射出光子的频率。

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