Attosecond pulse train
= Attosecond pulse train
An <attosecond pulse train> contains repeated short <optical pulses>. For a group of odd multiples of a common driving <frequency>, the separation is half the driving period when the relative <spectral phases> recur. The construction resembles <mode locking>, but the participating components come from <high harmonic generation>, rather than separate resonant modes of a <laser> oscillator.