Yellow/Green center

[millirad]

I have seen a lot of green lasers with higher power that are not running with an IR filter whose beam profile has a yellow/green center. Anyone else seen this? I have a theory about this and wondered what you think? I have seen some IR beams that featured a dim red coloratiion. Green DPSS is powered with IR as everone knows. Unfiltered greens have a substantial amout of multiline IR/green in the makeup of their output correct? See where I'm going with this? To create a yellow laser on purpose, as in the way Rog does it green+red=yellow in the correct proportions. Therefore it is my humble opinion that their is likely to be some yellow in the combined IR and green output. It seems to show up in the center of a powerful green. Thoughts?

 

[HIMNL9]

Don't know for sure, but i doubt about this ..... the emission of an 808 is dim red / dark red, but it's turned to 1064 from the first crystal, before go through the doubler and convert in 532 ..... the color is really low at start, ands after the first conversion, i doubt that remain enough power for interfer with the green part

But you need someone with a spectroscope for do some serious tests, in this field.

 

[scopeguy20]

It's a trick of the eye IMHO, the very bright color is perceived as whiter with many colors, although more truly a pure WL. If you notice a violet dot looks blue even on a non-fluorescent surface, and a blue 473 is more turquoise looking as it gets very bright too. Further a dot of a yellow 593.5 nm looks less orange and more yellow the brighter it is, and more orange when dimmer. So, too the green looks more toward the yellow as the light overwhelms the eye, and if dimmer looks further toward emerald, (blue direction), I think that's what you are perceiving. -Glenn

 

[Deleted member 8382]

I think it's just your eye. You can't distinguish the color when it's very birght andso you see it white, which may appear as a dim yellow.

Yours,
Albert

 

[phoenix77]

I tend to agree with scopeguy20's explanation of this. It's just an OPTICAL ILLUSION................rob

 

[millirad]

Thanks for the feedback! I can see how it would look more yellow just because it has more power, and not because the IR is coloring it. If there isn't any dim red making it through the crystal, then it wouldn't be having any effect. I can believe that no red colored IR is passing through the crystal. Confusing how an LPM picks up an unfiltered beam as more powerful unless its IR radiation escaping around the edges of the crystal.