Flash paper, Matches and lasers

[Milev]

hello, i hope everyone is doing great.

i have some qustions concerning flash papers :
i know that IR laser are the most invisible but what is the the least visible beam that can burn a black colored flash paper/ match?
dose the laser frequency has an impact of the out put power to burn a black colored flash paper / match?

the thing i'm trying to do is to burn a flash paper from a distance of a (50cm), and i want it when it seen , to be as if the flash paper vanished instantly buy it self .

feel free to modify or to give any other suggestions that can make project works.
thank you in advance.

 

[paul1598419]

If your flash paper is black the wavelength should have little to do with its ability to light on fire. Most of the flash paper I've seen is often white which would be more reflective of light than black would be. Keep in mind that the further away you get from your target the less tightly focused your beam will be. At 50 cm, or 20 inches, any tight beam of 1 watt in power should be sufficient to start it to combust.

 

[RedCowboy]

You have to be very cautious with invisible beams over 5mw, if you want flash paper to combust as if by magic and you intend other humans to view this you must understand the hazard of working with an invisible beam, there is a strong chance of an accident, if your laser were to stay inadvertently energized ( switches can/do fail to open ) you would likely not know and if that beam hits a spectator in his/her eyes you will have disabled someone for life and put yourself in serious legal/criminal jeopardy. Using an invisible laser over 5mw in a magic show is a very bad idea, accidents do and will happen and although you do have the right to take risks you don't have the right to put someone else at risk of lifelong visual disability.

 

[gazer101]

If you're going to be using invisible lasers, make sure that they are in the deep infrared (>1400nm) so that if they do hit someone they only burn their cornea and not their retina (corneas can be replaced afaik, for a price)