[Let us assume lasers are the basis of mobile suit beam weaponry and hence it's IC for her to know this stuff that I will bullshit all the way. Einstein is a freaking genius.]

LASER stands for Light Amplification by Stimulated Emission of Radiation. As the name describes, we need to conduct stimulated emission of photons. There are various ways to produce one, though we would be severely limited by available materials. What kind of laser are you interested in?