Problem with colour mixing 405nm into red 650nm

[mind_ripper]

Hello, i have made a small laser projector and combined the beams of both the 405nm @ 120mW violet and red @ 80mW. My aim was to get a nice pink colour. After i aligned the lasers you could see the pinkish colour. However when i projected onto a wall i got violet boarders at the top and bottom of the pink? I wonder if its possible to get an exact perfect pink colour without these boarders? Im also looking at doing other colours after i get this right.

 

[HIMNL9]

Probably, the focusing of your beams are not the same (if your violet is focused more large than your red, then you have a "circle" or "oval" shape of the red (with the long axis horizontal), overlayed to a little more large "oval" shaped dot of violet ..... if you have this, ofcourse the violet cause borders over the red (i'm assuming that you have used a PBS for combine the beams, if not, please let me know)

Anyway, you need to open a bit more the red beam, or if possible, better close a bit more the violet, so the diameters of the spots becomes the more similar, and this can reduce the halo effects (but remember that you can not have a perfect pink beam ..... you're mixing two different wavelenghts, not combining them for obtain a different one )

 

[mind_ripper]

yes, the violet is much bigger than the red. I will see if i can adjust the red to get a bigger dot, maybe this will help. thanks for the help.

 

[Jaseth]

What he said ^^
When you combine other wavelengths with 405nm, you usually want to make the violet beam thinner than the others. The combined borderline UV visibility, scattering and fluorescing effect of 405nm will make the beam look as wide as a baseball bat only a few metres away. The part of the beam close to you will appear thin while the part far away will always appear fat, so if you put the laser down and view it from the other side, it will suddenly be at the output that the beam looks thick.

Because of these properties of a 405nm beam it is very difficult to get a good mix with another wavelength, but widening the red beam and making the 405nm beam as thin as possible should help somewhat.

Seb

EDIT: 1337 post.. for the 4th time! A lot of threads being deleted it seems.

 

[KGB_Productions]

FYI...

This is what your "pink" should look like if you can get them to fit inside each other..
120mw 405nm
80mw 655nm

 

[mind_ripper]

many thanks for the tips, i will see what i can do!

 

[Cyparagon]

A projector's image is seldom a single stationary dot. It's not noticeable under normal operating conditions, and I wouldn't worry about it.