I found that green lasers have become more popular because they are more visible, but there is a risk of burning paper. This is caused only by the wavelength or higher power involved?
Sorry, what do you mean exactly with "risk of burning paper" ? ..... if you use a 200mW green, red or BR, and focus them good, you can burn paper with any of them (more with BR) ..... it's matter of how much powerful and focused is the laser, to burn or not ..... the color is important only related to the color of the object .....
@ photonicsourcing: said in brief, the color of an object depend from what wavelenght the object reflect away more ..... so, if you use a red laser on a red object, almost all of the light become simply reflected away, same with green, blue, and any other colors.
For burn something with a laser. the better system is to try to burn a complementar color object, that is a color that reflect away the less possible color of your beam (red for the green, green for the red, and so on) ..... or, better, a black object, that reflect the less possible from any color .....