Fluorescent Yellow
Saved the weirdest sample for last. Not a particularly exciting one. However it doesn’t follow suit with typical fluorescence. Also this sample is more translucent than the others. I started to doubt if I picked this one up by mistake. However the edges do glow under the right angles.
Something to note is the pmma didn’t show much signs of non-fluorescent emission when compared to longer wavelengths. You can see that the green and yellow bands are present like the other fluorescent samples. However most intense output occurred under green illumination rather than shorter wavelengths. 532nm created the greatest relative response overall. It may be possible to achieve some lime-green or yellow output with this sample.
Relative Intensity Spectrums
Conclusion:
Fluorescent Yellow is not a very good lasing candidate overall. This sample is a lot more translucent than other samples I have tried. Because of this absorption is lower, and therefore the ratio of emission vs pump intensity is low with all being below 100%. 406nm has the best yield however its peaks are low. The next highest yielding wavelength that also peaks the highest is 532nm. Despite the poorer yield, this may be the best pump for this PMMA. By the looks of the results, it appears that this unknown sample is an equivalent of Perspex® Helios Yellow but with lower dye concentration. The strongest peaks are between 556-562nm and another in the yellow part of the spectrum (583-586nm). A weaker band also is present at 504-514nm with only 406nm being potentially capable of lasing it.