a while ago I tried to charge a glow-in-the-dark sticker using a simple red laser pointer. It was a large sticker, of the type used to mark emergency exits and fire extinguishers here in Germany. I thought I could draw a picture this way, with glowing strokes.
To my surprise, the exact opposite happened - the sticker was already glowing a little bit and the areas I illuminated with my laser turned dark instantly, as if the charge of the sticker was removed by the laserlight.
The effect was reversible, the darkened areas would charge and glow as usual if exposed to normal light.
So I was able to draw a picture after all - however, it was a negative.
Can anyone explain why the sticker was discharged instead of charged by the laserlight?