The finite bandwidths of the driving and the probe field decrease the gain and change the value of the index of refraction, especially of the driving field. 激發(fā)場(chǎng)線(xiàn)寬破壞了原子的相干性,使介質(zhì)的增益下降并改變了折射率的大小,探測場(chǎng)的線(xiàn)寬使介質(zhì)的探測增益譜及折射率譜的分辨率下降。