Ponderomotive force and conservation of momentum

[Philip Koeck]

According to https://en.wikipedia.org/wiki/Ponderomotive_force a charge in an inhomogeneous, oscillating electric field will be accelerated in the direction where the field gets weaker.

One could think of a charged particle placed slightly off-center inside a laser beam.
If I read the Wikipedia page correctly this particle should be accelerated away from the center of the beam.

What would happen to the laser beam during this process?

 

[Dale]

There is a theorem like Poynting’s theorem, but for momentum. As the momentum of the particle changes, the momentum of the EM field changes in the equal and opposite direction.