RGB+CV Laser

[FireMyLaser]

I'm in the process of making a portable white laser. I've already made a complete RGB version, but now I want to add 488nm cyan and 405 violet.
Here is what I made so far:















This is the plan to make RGB+CV:
View attachment rgb optic.png

This schematic shows how the laser is made now. Some changes will have to be made when I add the extra wavelengths of course. The buck wont be needed when I replace the DPSS for a direct green diode.



Stay tuned for more. Hopefully I wont screw up an already excellent RGB build.

 

[RandomName123]

Damn! That awesome looking!

 

[hakzaw1]

WOW
Your pics are greatly appreciated-- I want your camera''lol
This thread is going to be HUGE.


+1rep
& 5 stars

hak

 

[FireMyLaser]

My camera is my Oneplus 5T phone, I think it's pretty good.
Now I think I'm nearly done adapting the circuit to use two more channels. It needs few tweaks and hopefully somehow fit in the laser.

Anyone know that the state is with DTR's shop? Last I ordered 10pcs G-8 lenses but found out that their focal length is way too long. Not even possible to use with red diodes. I'm trying to get help from him regarding this, and I consider getting 10pcs G-2 lenses instead. But I don't want to waste the money if they also have problems. My emails don't get answered.

I ideally I want the beam for each laser aperture to be about 3-3.5mm in diameter, and have a low divergence (the diodes I'm using are all single mode).

 

[Snecho]

My camera is my Oneplus 5T phone, I think it's pretty good.
Now I think I'm nearly done adapting the circuit to use two more channels. It needs few tweaks and hopefully somehow fit in the laser.

Anyone know that the state is with DTR's shop? Last I ordered 10pcs G-8 lenses but found out that their focal length is way too long. Not even possible to use with red diodes. I'm trying to get help from him regarding this, and I consider getting 10pcs G-2 lenses instead. But I don't want to waste the money if they also have problems. My emails don't get answered.

I ideally I want the beam for each laser aperture to be about 3-3.5mm in diameter, and have a low divergence (the diodes I'm using are all single mode).

DTR's shop is currently being run by @aug. Try sending him a PM, he replied to my lens question within hours.

 

[RedCowboy]

Very nice, I love it and your open air fiber coupler is very cool to see working.
Anyone can buy something but this is the kind of homemade eye candy so many love to see, I know I do, thanks for sharing and I look forward to seeing your addition of 488/405nm although it looks like you have a nice white output right now.

 

[Alaskan]

Very nice, and nice wiring and circuit board work too.

 

[FireMyLaser]

Thanks. (Still no pm or email response..)

 

[FireMyLaser]

Aug doesn't know the properties of the G2 lenses, in fact he doesn't seem to know how lenses work at all. I wasted a week trying to get him to answer. Does anyone else know what to expect from G2 lenses? I need to know the approximate beam diameter at aperture, divergence, and if those will match with single mode red/green/cyan/blue/violet diodes. Or should I use a different lens for this project?

 

[RedCowboy]

DTR-G2 also known as a 405-G2 is a 400-700nm broadband AR coated single element short focal length and I thought it was 2.39 EFL but DTR's page says it's 4.00mm EFL and 2.40BFL, NA=0.60 and 96% transmission

What lens are you using on your RGB ? I actually like the G3 on my 488's, it's also a single element broadband coated but longer FL but not as long as the G8.........you will likely want to use the same lens for all your diodes but if acrylic for low output green you can't use acrylic for 500mw 405nm as it will melt, G3 might be a better match.

G2 will make a thin looking beam in the near field and will be wider in the far field.......I'm sure you know this.

Maybe someone knows exactly what single mode diodes and lenses match up the best and the exact beam specs with each, I just go by aesthetics as for my single modes.

 

[FireMyLaser]

I don't know what lenses I'm currently using, both are different for red and blue, and I got them here on the forum long ago, around 2010 give or take a year, which is why I no longer remember. They have different AR coatings but similar beam profiles. Around 3mm at aperture. I need a thin beam because the combining optics are are so small.

 

[RedCowboy]

The shorter the focal length the smaller your beam at the aperture but the wider in the far field......the longer the focal length the wider your beam at the aperture but the smaller it will be in the far field.

3mm beam......I would go with a G3, Looking ( through my laser safety glasses ) at my 488's I have about a 2mm by 4mm beam/spot at the output using a G3 and my BDR-209 ( 405nm ) with a G2 is about the same, this is with both lasers focused to infinity so G2 for your 405nm which does look the best IMNSHO and G3 for your 488nm or you could use an acrylic for your 488 but it will rob power, I drive my Sharp 488's @ 250ma for about 100mw with a G3

 

[FireMyLaser]

I only wish to use only type of lens for all diodes:
638 GH0631IA2GC
520 PL520B
488 GH04850B2G
450 PLT5 450B
405 BDR-209

What is the difference between G2 and G3? If the beam characteristics are the same, then I want the more efficient one.
If they have the same efficiency, then I want the one that's better far field (assuming the aperture beam does not exceeded 3mm).
I will not use plastic lenses though.

 

[RedCowboy]

All laser diodes are not the same, that is all single mode laser diodes are not the same emitter shape/size/divergence so you may want to use different lenses.

G2 is the most efficient but yields the worst beam divergence, the G8 is almost as efficient and yields much better beam divergence, the G8 is longer focal length of about 8mm.......the G3 is in the middle and is not as efficient but it's not bad, better than multi-element or acrylic.

I usually only use G2's for my 405nm and for multi mode diodes before cylindrical pairs because the beam diverges so fast, I would probabally use G3's if you also want to keep the beams around 3m, the beam in the night air looks great with G3 or G8 but not as good with G2 because of the divergence.

 

[FireMyLaser]

Cool, thanks. I've seen that picture on DTR's shop, but I have two problems with it.
It uses a multi mode diode which is quite different from single mode, and even though the G8 is supposed to have the lowest divergence (it sure has a FAT aperture beam), yet somehow the G3 makes the smaller dot in this picture.

My logic was that it would mean that the G3 would have fatter aperture beam than G8. So is the picture wrong?

Btw, I don't need the beams to be *exactly* the same, but approx 3mm or less at aperture, and I'll intentionally de-focus the other four lasers to match the one diode with the highest divergence.

 

[Alaskan]

Regarding that photo of beam spots, to be of most value as an example, DTR's photo's of the beam outputs should have been done at the same distance from the lens, judging those are window blinds in the background, at least the camera was the same distance from them and I would hope the lasers were too. I'm surprised how large he spot is from the stock ball lenses, terrible.

Firemy, I don't understand some of the wiring in your optics, I see something on top of the PBS and rotator, what did you wire up there?