In the wikipedia article,en.wikipedia.org/wiki/Gaussian_beam,it is written that laser beam is gaussian and that it is described by a spot radius. But this is given independent of using lens. Is it saying that laser beam when it comes out of cavity initially converges and later diverges. Please make this clear to me.

Isn't the force due to circularly polarized light given by average of forces due to two electric fields separately? And how do you explain the force due to unpolarized light?