Admittedly, my interest in lasers is generic at best - I've seen "Real Genius" too many times growing-up in the eighties and had a mild obsession with the "Las-Gun" in "Warhammer 40k"...I would like a proper introduction regarding the nature of Light Amplified Stimulated Emissions of Radiation, please, as I would like to understand more than just burning power in the John Woo/Chow Yun Fat "Hard Boiled" sense.