@cube777 I wouldn't judge your teacher, but you're VERY lucky for a 405nm to reach 1W power. My 500mW one can put holes in white paper. But, you're right, 405nm has more energy per photon, however it's not really that characteristic that makes it burn better, 405nm is absorbed much more easily in most materials than other colors, and the diode itself it single-mode, which allows for a much more tight beam (higher energy density)
Everything has been covered for the OP in my (remaining two) eyes.
What kind of power (mw) can you get out of a blue ray burner. There are a few 405nm at 600mw on ebay. I didn't know you could get that strong of a laser from a burner. If thats correct then what keeps the laser from burning through the disk