Take the tour ×  Similar questions have been asked before, but
this one extends the scope of interpretation and applications.
Let us ask the question: What will happen if we have a laser gun
that produces a high intensity laser beam, of the order $10^{15}
Wm^{-2}$ say, and frequency about $4\times 10^{14}Hz$, and shoot
a hydrogen atom in its ground state? The duration of the laser
pulse is sufficiently long. Answers in terms of physical
arguments will be appreciated.  share|improve this question
@Emilio Pisanty Thank you for all this valuable information.
Much appreciated. –  JKL Feb 13 at 17:36 @VladimirKalitvianski
Thank you for your answer and the information you have posted.
Appreciated. –  JKL Feb 13 at 19:16 add comment  2 Answers  up
vote 3 down vote accepted  For low-frequency, high-intensity
laser fields, atomic and molecular targets can be ionized by
multi-photon ionization (which is a nonlinear process and thus
requires high intensity, but is nevertheless possible) as well
as tunnel ionization (wh