Although light waves in the regime of classical optics can have electric fields as strong as those near bolts of lightning, these fields are not effective for accelerating particles on their own, because they oscillate transversely.

• 在古典光学中，虽然光波的电场有可能大到如闪电雷击的程度，但因为电场是以横向振荡的，所以无法有效用来加速粒子。