3 ms·
Yes, of course, there is some offset between the absorption range and the emission wavelengths. But there is no requirement for the absorption to be in the UV r
by _ph_ 7y ago
Yes, of course, there is some offset between the absorption range and the emission wavelengths. But there is no requirement for the absorption to be in the UV region. The absorption range is also wide peak. All the fluoreszent colors which "work" with e.g. car headlights have a sufficiently strong effect in the visual range.
It is also an easy test for fluorescence to shine e.g. a blue light at something which has a strong orange color. If it still is strong orange, fluorescence obviously is the dominating effect.
I don't doubt that UV light shows a strong fluorescent effect, especially as you cannot see the UV light itself, but of course the fluorescent emission it is causing.
- mannykannot 7y agoIs there much use of fluorescent colors that work in car headlights? For signs and markings, reflective paints seem to be more effective in showing up under headlights, particularly as the light is directed back towards the source, rather than scattered widely. The article below describes the benefit of fluorescent dyes under weak natural light, as they can use the UV component of natural light to increase the amount of visible light reflected. Downshifting visible light to a longer wavelength, which is what fluorescence excited by visible light would do, would reduce the intensity of the reflected light. https://www.3m.com/3M/en_US/road-safety-us/resources/road-transportation-safety-center-blog/full-story/~/fluorescent-traffic-signs-explained/?storyid=e33bd3e0-36b0-44c0-b416-1b87324b2755 https://www.3m.com/3M/en_US/road-safety-us/resources/road-tr...