Just joined the forum, originally from Alaska, currently having a home and family there I will return to when done working in Iraq as a civilian SATCOM engineer supporting US Army tactical satellite system to provide telephone and internet. I joined the forum to research some of my physics questions in regard to solid state lasers as well as laser optics. I am very active on the laserpointerforums as "Alaskan" there too. I found the forum when yahoo'ing a question regarding uranium glass to understand the transitions which produce a glow. So far, I've learned when the atoms are excited by UV, the glow is 550 nm. I am trying to determine if the green light produced is wide band over a spread of a few nanometers, or whether narrow lined at 550. If you know the answer, please do not respond in this thread, just letting you know what brought me here. Regards, Christopher Edit, I'm in Iraq, why did I write Iran.... I guess I've been reading too much in the news about Iran lately.