Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



My first yellow build...updated with yellow beam!

grainde

Well-known member
Joined
Jan 29, 2012
Messages
3,159
Points
113
Well this will be an ongoing build thread for my first attempt at a combined yellow laser. I will try to detail what worked (and what didnt), which should help you avoid making the same mistakes. ;)

The laser is actually almost complete, but it looks like I may have to dismantle the optics once more as I think I have figured out some of the issues with the dot - more on this later.

So the things you will need are:

1) Dual diode host - Im using this from Ehgemus. There have actually been a few build threads and from what I have seen Rogg, Jayrob, [URL="http://laserpointerforums.com/f40/yellow-tri-mag-90107.html"]Jayrob again![/URL] and Jander have made some incredibly impressive builds!

2) Two single mode diodes. Here Im using the PL520 and the Oclaro 170mW

3) Optics. Here I decided to use a first surface mirror from a projector and the turning mirror from a PHR-803T sled. Here I used an old PHR optic, but decided to get a couple of extra sleds for one more similar build I have planned. O-like was actually the cheapest source I found, but I have to admit that I did have issues once I had paid them. They were exceedingly quick to answer my questions about the payment, but once the transfer had been made there was absolutely no contact with them. After just over a week and 4 emails my order was still pending, so I opened a dispute, only after this did they bother to respond stating that they had shipped. According to the tracking, they actually shipped 2 days after I opened the case.:gun: I have left the case open and will keep it open until the items actually arrive. Due to this I cannot recommend them as a source for the sled as I would actually consider them a risk. Anyway I will keep you up to date with any new developments.

4) I would highly recommend the use of mounts for the optics. After having spent many hours playing with some copper wire, tape and epoxy, I can definitely confirm that an adjustable solid mount is the way to go. Unfortunately I only have a max of 13 mm to play with and so that wasnt an option here.

5) You should use the same lenses. This is important not only for the dot but also for the beam diameter/ cross section. Initially I started with a red acrylic on the 638 and a G9 lens on the 520; yes G lenses on single modes still give a nice dot, but the longer focal length of a 3 element and less splash make these a better choice. Remember to use the correct coating for the wavelength used.
2 Acrylics will also work, but there maybe artifacts/ splash around the dot. Edit I have now moved to dual acrylics as the 3 elements simply loose too much power. With the 3 element I was getting only 40 mW green and 30 mW after optics, with the acrylic this increased to 70 mW before and around 57 mW after the optics (PHR). The red also increased from 140 mW to 198 mW (the optics didnt make much difference to the power as the transmission above 600 is only around 1 %).

6) Drivers. Well you need to run both diodes with the same battery configuration and so you will need to choose your drivers carefully! ;) Here I chose a buck for the red. As the Vf of the red at around 200 mA was 2.7 V the buck would stay in regulation, even on one battery. For the 520 with the very high Vf a boost was the way to go and as this also runs off one battery we were set to go. The two drivers used were and X-drive (buck) V6 and an X-Boost V7 mini. I actually asked for these drivers with pots as I wanted to be able to adjust the current once the alignment was correct in order to obtain the best colour mix.

Here are a couple of pics of the build so far:







and in action:






As you can see in the last pic there is just a little too much red to the RHS. there are also a couple of minor issues with the alignment that need correcting. But as I mentioned above, I may have to completely realign the optics and possibly rotate one of the diodes 90 ish degrees, which will mean effectively rebuilding. :undecided:

Well thats all for now, I will update tonight with more specific info on the build and a few more pics.:beer:

Update: After several hours repositioning the diodes, refocusing, regluing the optics and realigning them, this is the result:):beer:



Update:

After decicing to replace the mounts with adjustable ones, I spent a few hours with a saw, dremel and leatherman and came up with this!



Unfortunately at approx 1 cm2 it was too big so back to the drawing board- this was the result (one on the right);):



Now to give you an idea of size this is my thumb and in the second photo an aixiz focus ring!



In the end I made 2 of them as Im making two identical yellow builds - one will be an xmas present;)



The dimensions are 1 cm x 0.6 cm x 0.4 mm (base where stands). Now I just have to wait for the new dichros and I should be set to go :):beer:
 
Last edited:

3Pig

New member
Joined
Oct 26, 2013
Messages
246
Points
0
Re: My first yellow build...

Very nice, I've been looking to do something similar after looking at jayrob's yellow builds.

Would an LPC-826 and a DPSS 532 module work?

Can't wait to see it in action :D
 

grainde

Well-known member
Joined
Jan 29, 2012
Messages
3,159
Points
113
Re: My first yellow build...

Yup that will work too. :beer:

Updating with couple more pics! :)
 

jayrob

Well-known member
LPF Site Supporter
Joined
Sep 21, 2007
Messages
9,867
Points
113
Re: My first yellow build...

It's tricky combining to get yellow...

Not only needing perfect alignment, but getting good balance of power for yellow...

It's fun though! :cool:

I see you linked my thread. +rep

In my Yellow Tri-Mag thread that you linked, I give output power measurements for each laser. Maybe that information might help with your experimenting...

:beer:
 

grainde

Well-known member
Joined
Jan 29, 2012
Messages
3,159
Points
113
Re: My first yellow build...

Thanks for the pointers and yes tricky is an understatement! :)

I had a look at your currents, but here Im using a 638 so its power will probably need to be slightly less. I was actually planning to dial in the current, once the alignment had been done. The idea was to set the red and green at their respective maxes ie 350 mA and 250 mA and then slowly turn back the green to the "best yellow" ;) This is why all the leads are still hanging out the back of the head. :)

Anyway, Ill definitely compare your OTF green readings to the ones I get and post them here for future reference! Chances are my green will have to run harder too, as my dichro (turning mirror) is not optimal for 520 nm.:thinking:

Anyway not quite as impressive as your build, but shes coming along! :beer:
 
Last edited:

crazyspaz

New member
Joined
Jul 4, 2012
Messages
2,863
Points
0
Re: My first yellow build...

Looking awesome! I have had a few ideas for a RG build, but just never got around to doing any of them. Maybe I will at some point, at least I hope I can. Just haven't been able to decide what the best method for alignment would be. One idea I had was to mount the adjustable optic (just use a bounce mirror for the other diode) on a set screw with just a smooth bar on the other side that slotted into a hole- hard to explain, what I mean is something like this:

So with a small hex bit you could ever so slightly turn the dichro to proper alignment, then epoxy it in place. Dunno how practical it would be, and I am sure milling such a tiny part like that would be a b!$&$ and a half.
 
Last edited:

Atomicrox

Well-known member
Joined
Jun 22, 2011
Messages
2,432
Points
83
Re: My first yellow build...

Keep in mind the "warm yellow" from a combination using 520nm won't look as good as one made with 532nm. That's why the projector folks prefer 532nm.
 

USAbro

Banned
Joined
Oct 16, 2014
Messages
1,310
Points
0
Re: My first yellow build...

This is really cool. I think the theory behind combing the wavelengths is amazing! Can you get aquarius blue from mixing 532 and 450?
 

grainde

Well-known member
Joined
Jan 29, 2012
Messages
3,159
Points
113
Re: My first yellow build...

Looking awesome! I have had a few ideas for a RG build, but just never got around to doing any of them. Maybe I will at some point, at least I hope I can. Just haven't been able to decide what the best method for alignment would be. One idea I had was to mount the adjustable optic (just use a bounce mirror for the other diode) on a set screw with just a smooth bar on the other side that slotted into a hole- hard to explain, what I mean is something like this:

So with a small hex bit you could ever so slightly turn the dichro to proper alignment, then epoxy it in place. Dunno how practical it would be, and I am sure milling such a tiny part like that would be a b!$&$ and a half.
Ive been improving the mounts and am now using a thin strip of copper grounding strap from an HF radio. They are strong but easily bent, the plan is to epoxy them into the rough position required and then bend gently until the beams are correctly aligned. I can then add a big blob of epoxy to keep them from moving.

Yes I ripped the whole thing apart again today and made sure the diode beams were perfectly parallel...Also blew up the xdrive by not paying attention to the polarity...:( A new one has been soldered in now though and Im currently retesting.:beer:

Keep in mind the "warm yellow" from a combination using 520nm won't look as good as one made with 532nm. That's why the projector folks prefer 532nm.
Wouldnt it be a colder yellow with 520? If it is, you should be able to balance that with perhaps a 650 instead of a 635. I have noticed that the dot is a very "bright" or light yellow and not a deep saturated one. Anyway Im still playing with it to get the ratios correct.;) :beer:

This is really cool. I think the theory behind combing the wavelengths is amazing! Can you get aquarius blue from mixing 532 and 450?
Thanks.:) Yes you can get a cyan from mixing those.:beer:
 
Last edited:

Atomicrox

Well-known member
Joined
Jun 22, 2011
Messages
2,432
Points
83
Re: My first yellow build...

Wouldnt it be a colder yellow with 520? If it is, you should be able to balance that with perhaps a 650 instead of a 635. I have noticed that the dot is a very "bright" or light yellow and not a deep saturated one. Anyway Im still playing with it to get the ratios correct.;) :beer:
Yeah, it would be colder. Not sure if you can compensate with 650nm, better wait for someone that actually knows about projectors :p
But even if you can you'll lose a lot in beam visibility :/
 

Blackwolf

New member
Joined
Jul 12, 2013
Messages
348
Points
0
Re: My first yellow build...

Would an LPC-826 and a DPSS 532 module work?
that would be much more difficult to align. DPSS lasers do not come out of the aperture in a straight line, and the divergence for DPSS laser is much better than a diode which would also add difficulty to alignment.

Can you get aquarius blue from mixing 532 and 450?
If you mean LG Aquarius-473 then no it is more an Argon-ion which would be in the cyan range as mentioned above (480nm+) it is still a nice color though

better wait for someone that actually knows about projectors :p
From reading threads on PL I think they would say the best way to get yellow in the mix is to use ≈575nm. Based on the chart I saw on PL using 520 instead of 532 cuts hundreds if not thousands of yellows oranges and browns out of your display.
 

Ehgemus

New member
Joined
Feb 28, 2009
Messages
1,385
Points
0
Re: My first yellow build...

Great job on the build. Got any beam shots?
 

grainde

Well-known member
Joined
Jan 29, 2012
Messages
3,159
Points
113
Re: My first yellow build...

that would be much more difficult to align. DPSS lasers do not come out of the aperture in a straight line, and the divergence for DPSS laser is much better than a diode which would also add difficulty to alignment.
Yup matching the beam diameters could well be an issue, chances are too the divergence on the 532 will also be much better than the diode. This would make focusing the dots difficult, as the sizes will vary over distance.

From reading threads on PL I think they would say the best way to get yellow in the mix is to use ≈575nm. Based on the chart I saw on PL using 520 instead of 532 cuts hundreds if not thousands of yellows oranges and browns out of your display.
Interesting, Ill have a play with the currents tonight to see whats possible. It seems like the colour range I have though, goes through the lighter shades rather than the deeper more intensely saturated yellows and browns.

Ehgemus said:
Great job on the build. Got any beam shots?
Thanks wouldnt have been possible without your host.:) I re-glued the optics last night and will try to sort out the alignment today. Once thats done, Ill post some beam shots. Any news on the other host? :beer:
 

Atomicrox

Well-known member
Joined
Jun 22, 2011
Messages
2,432
Points
83
Re: My first yellow build...

that would be much more difficult to align. DPSS lasers do not come out of the aperture in a straight line, and the divergence for DPSS laser is much better than a diode which would also add difficulty to alignment.
Strange, I don't have a single 532nm laser with divergence better than my single mode diodes, specially the red ones. But then again I only have el-cheapo 532nm lasers.
 

grainde

Well-known member
Joined
Jan 29, 2012
Messages
3,159
Points
113
Re: My first yellow build...

From what I understand diode lasers have a much shorter cavity than than DPSS lasers so the beam specs have the potential to be much better. Single mode are however very close. I have a DPSS green 5 mW that has these specs:

Beam Size At Aperture (mm)
3
Minimum Beam Divergence (mrad)
0.1
Pointing Stability (mrad)
0.02

Perhaps single modes can be that good, but Im not sure? :beer:

Edit: Specs - http://www.global-lasertech.co.uk/our-products/green-532nm-laser-diode-module-range/firefly-532nm-green-laser-diode-module/
 
Last edited:

Atomicrox

Well-known member
Joined
Jun 22, 2011
Messages
2,432
Points
83
Re: My first yellow build...

Wow, those specs are amazing. I don't have any laser that gets even close to that.
 




Top