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Using 638nm and 520nm to make a yellow combined laser

SuckPit

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Just had a quick question. I'm planning to try and put together a yellow laser by combing 638nm and 520nm and I wanted to know what a good blend would be for a "perfect" yellow. I'm looking to get around 50-100mw combined power. What do you think would be a good ratio for it?
 



Lumenati

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Firstly, I'd recommend using 532nm for the green, as the color ends up being much closer to that of a true 589/593nm (I've built both, with 520nm + 638nm the color is yellow, but looks 'washed out' as 520nm veers on the 'blue' side of the spectrum). Regardless of which wavelength you choose, I'd say for 100mw, 70-80mw red + 20-30mw green would make a good ratio; and for 50mw, 35-40mw red + 10-15mw green (best to use drivers with pots too, for adjustments).
 

SuckPit

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Cool thanks! My only problem is most 532nm are dpss and have much small beams than 638nm. That's why I was thinking about using a 520nm for slightly bigger beam size to go with the 638nm. I'll probably try out both 532nm and 520nm and see how big the difference is. Thanks again!
 

Encap

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Unless you want to make a hand held which would be very difficult and expensive if you have the skills to make one, you might want to look at RGB modules on eBay which are low cost $50 to $80 depending--
Use the R and G don't turn on the blue. There are several available some with 532nm and some with 520nm.
See: https://www.ebay.com/sch/i.html?_fr...ule.TRS1&_nkw=RGB+white+laser+module&_sacat=0

Hope you realize it is not possible to make a yellow wavelength laser by combining red and green laser beams.
All you will have is an illusion of some sort, depending upon your visual system, of yellow at best if both lasers are perfectly aligned and both lasers have same beam shape and size which is still just a red and green laser laser beam not a yellow laser.
Color is not a physical property; it is merely the brain’s interpretation of different wavelengths of light. Color names are words/symbols for that brain activity.
 
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hakzaw1

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WHAT HE SAID^^^^
I have both and a true yellow HeNe looks so much better and has no duty/rest cycling
those 'white' lasers are a good deal-many to choose from-and there are kits too.
BTW 'yellow' (and 'orange')_HeNes are very spendy and some like mine only makr 6 or 7 mW BUT WOW
-

they-make a much better yellow LUMIA--with a combined yellow the glass seperates much of the red and green. just like a diffraction grating-surface of a dvd.cd disk etc--I prolly paid too much BUT buying an olde school yellow from Dr Sam (THE laserman)
made it a better deal--IIRC $300 for tube only-no PS came with--I had Sam put his autograph on the laser. IF you do not know who SAM is---but Sam and friends have most everything you may need to know on-line FREE and no ads etc however PLEASE do not contact Sam if you have NOT really tried to find help via google and our search LPF.
during my time at LPF I would say MYB 3 or 4 (out of thousands) questions asked here should be sent to Sam-- the rest---asked/answered a bunch of times.



btw when we get help from Sam be sure to say TY and mention the forum--Sam reads it all

hak
 
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SuckPit

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I got a RGB module from techhood it works okayish, the pwm on it is rather meh. I want to try and make RG analogue one for the challenge. I had a Spartan 30mw 589nm from DL for a while but sold it a while back since I was moving around a lot and didn't want it to get broken. I've been browsing these forums for about 5-6 years now, but only recently made a account.

One more quesiton does anyone know of some small analogue drivers that I can attach a 10k Pot on for external control? It seems the BlackBuck 8M are all sold out and not being made anymore. Even asked Barnett but he said he was also out of them.

I don't know if you saw it or not but I also did say thanks in my original reply. You don't really need to tell me to do something when I already did it.
 
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SuckPit

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Yep, I've already search the forums, the main ones that had info for me was Jayrobs Mag and his pointer. But I figured I might ask now since those were years ago. I was even thinking of using a PHR sled (kinda like the white fusion builds) to make it but it seems there isn't anyone that sells them.
 

Encap

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hakzaw1

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these help me a lot..ac1ecd_1be9ef19f2cb4345982766c9f35799d2_mv2.jpg

another view is needed-the 'other' pins are wire-solder friendly --not round but "U" shaped so a tinned wire slips in and you finish with a quick touch of your iron--so if a diode fails you can unplug the bad and push in a new diode.
these are better for 5.6mm diodes.

aixiz.com/accessories
 

aaronnoraa

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Just had a quick question. I'm planning to try and put together a yellow laser by combing 638nm and 520nm and I wanted to know what a good blend would be for a "perfect" yellow. I'm looking to get around 50-100mw combined power. What do you think would be a good ratio for it?
Don't worry about the output power, output can always be changed with the driver and you'll want to set that by eye anyways to get what you think is the shade you want.

Much more important is using diodes with similar cross section sizes and divergence. You will absolutely need to use a single mode 638nm diode. There's only a handful of choices above 30mw, so I'd choose one that most closely matches the divergence of one of the few 520nm diodes available. THAT will be the most important factor in whether it looks like a true yellow beam, or a yellow beam inside of a red beam.

Also, perfectly overlapped red/green do make a convincing yellow beam if done properly. I have combined an 11.5mw He-Ne with a 100mw DPSS (with the output reduced using the driver/supply) which had identical output cross sections and near identical divergence using a reflect green/pass red dichro plate and the yellow beam and spot looked like a yellow laser. The only thing suggesting it wasn't was the dust speckle on the wall (obviously) didn't overlap so outside the spot had red and green speckles. When the output mirror/IR filters were clean you couldn't tell that it wasn't a yellow laser.
 

hakzaw1

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Have you done any LEMs?
Once this pandemic goes away there will be LEMs again--while these gatherings are not always big- we make up for that.. there are some great members not too far from you.
Some in Canada. Some awesome members in Portland Or. ---- when they hold LEM I am going.
to see ytube vids search 'SELEMLaser' great but the vids are no way as nice as in person.

Stay well

best
hak
 

lasersbee

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Yep, I've already search the forums, the main ones that had info for me was Jayrobs Mag and his pointer. But I figured I might ask now since those were years ago. I was even thinking of using a PHR sled (kinda like the white fusion builds) to make it but it seems there isn't anyone that sells them.
If you are looking for some PHR Sleds... contact
me through our website in my Sig. I may have
some left.

Jerry
 

SuckPit

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Will do Hak! Thanks Jerry, I'm going to hold off for a little bit since I got some other projects going on right now.
 




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