White lasers are, unfortunately, an impossibility. Visible lasers emit a very narrow wave length of the color spectrum and that is it. White light, by definition, is every color in the spectrum combined. There are RGB lasers, but like LED RGB, they really don't make white so much as a shade of pale blue.
The closest I have seen had 6 different laser wave lengths joined together. It wasn't very powerful because off all the refracting done and was still more of a pale pink then a white.