I hope I'm wrong, but this seems like a lot of other "firsts". I'm guessing the total (and I mean -total-, lasers typically aren't that efficient) energy put into this will be much greater than the output.
MJ, not mJ. 2.5mJ is roughly the energy of a single keyboard keypress. 2.5MJ is over half a kilo of TNT.
Fun fact that Wolfram alpha just informed me of: a phone uses between 10 and 20 MJ a year: multiple kilos of TNT. 4000mAh * 3.7V * 365: yep, it's about right.