- Sep 5, 2013
This may sound like a silly question but are you able to get any sort of beam at all with your laser styropyro? I'm sure in a dark room, with fog, and a dark adapted eye, you'd see at least a gray beam or something?I've done a little more reading about the effect where the red laser kills the glow from the GITD surface. Wikipedia's article on phosphorescence gives enough background for this. Basically when a phosphorescent material is excited, instead of dropping down to the ground state quickly like seen in fluorescence, the electron in the excited state undergoes an intersystem crossing to a state of lower energy but higher spin multiplicity. The electron becomes trapped here because the transition between this triplet state and the ground state is actually forbidden by quantum mechanical selection rules, and it takes perturbations from the surroundings to change the geometry of the molecule enough to make the probability of this transition nonzero. But when we hit it with the red laser (which does not have the energy to excite the GITD material on its own) it excites electrons trapped in the triplet state, which then have enough energy to make an intersystem crossing back to the singlet state, and from there it can emit nearly immediately by fluorescence and fall back down to the ground state.
I think. I should be more comfortable with this stuff considering I'm trained as a physical chemist...