My first homemade 1W 808nm portable laser

This time I wanted to make something more powerful.

I decided to make 1W 808nm portable laser pointer because IR diodes are very cheap today.
Choosing a host was really tricky. After all I bought this one (DealExtreme: $19.90 Cree XR-E LED Flashlight Complete DIY Body Shell/Casing Kit with Driver Pill (4*CR123A/2*18650))

Quality is the best for its price. I never had better host.
Here is how it looks like:



I bought two 1W diodes from ebay for about $30 and that was really good deal.


To regulate current I decided to use LM350 but that is far from perfect regulator.
I used 1ohm resistor to set current to 1250mA and laser worked but there is lot of heat dissipation. Regulator heats more than laser diode. I didn't worry about that because of big heatsink.
Everything is stable and that is all what I want.

But now I know that I could use AMC7135 that is much more efficient and I could use one 18650 and not two. After I bought $20 host I couldn't buy another.
However , I know that I'll use AMC7135 in every future IR build.

Here are pictures of module in heatsink and regulator:



As LM350 is positive voltage regulator and diode is case positive I had to electrically isolate module from host but to provide good thermal conductivity.
For this purpose I decided to use thermal tape.


I was afraid that it might not isolate heatsink from host but I was wrong.
It's not only thermal tape that provides electrical isolation but also host and module.
Both host and module are anodized and do not conduct electricity.
So there is no way that module can get in electrical contact with host.

I started with this IR build about 6 months ago and it was really difficult to find 9mm module.
Then I found it on Rayfoss for $12. But they don't produce these modules anymore.
But there is O-Like that sells 9mm modules for $4 (without lens). Just contact Susie if you want these modules.
Also there are lot of 9mm modules on ebay now.

I also included LED so can know when laser is ON. You never know what could happen..it's just for safety.

The most problems I had was because of lens.
Aixiz glass lenses are really small and with 5mm FL and not all light can go trough lens.
To provide as much light out as possible I decided to flip all lenses and to extend hole in aixiz lens assembly. I also extended lens holder so I can use focusing ring.


Now it's better than before but still not perfect. I should use cylinder lens to correct fast axis but I really can not find good cylinder lens for this purpose.
I bought one from Surplus but it's not good lens for 9mm diodes.

OK, Here are some pictures:



And Video:
YouTube - 1W 808nm IR portable laser

I also did test with Nd:YVO4/KTP crystal pulled from dead laser pointer.



And video:
YouTube - 1W 808nm IR portable laser and cheap Nd:YVO4/KTP crystal

Thanks to all LPF members.
I'll never be able to build this laser without their help.

How is that green collimated?

Nice project, well done!

There are two crystals in holder (Nd:YVO4 + KTP) and beam is TEM00 so you can see good beam with not that bad divergence.
That is all done by crystal.

To achieve better divergence you need more optics (that you can find in cheap laser pointers).

Very nice build!

I have a DX 100mW true module which I ripped to shreds, I have pulled the crystal assembly off the front to reveal the diode and powered it up, it burns without being focused.

If I could find a suitable module I may get one, I know Meredith do one so I may get one of those.

Once again great job, looks like a really nice laser

Thanks!

Yeah, Meredith are great and have 4.5FL glass lens but they cost much more.
I think O-like is best buy ($4 module + $5 glass lens)

If I had a money I would buy Meredith without thinking.

Hmm I was asking others in the forum on how to switch an ir diode into green and they said it was pretty difficult. This picture shows you pointing the beam through a crystal and that's about it. This doesn't look too hard really.

Thanks for the inspiration. Do you by any chance have a mw measurement on the green after it has been processed? Does the crystal change the output much?

I don't have LPM and I can only adjust it by sense.

It's easy because I have collimated beam.
Cheap laser pointers use just diode close to crystal and this method is a bit more difficult.

In both cases power vary very much when I change position of beam.
It's very tricky to adjust it to output the highest power of 532nm but it can be done.

I had some problems with 50mw DX module. It starts with pretty high power and than after few seconds power starts to descend and it becomes like 5mW laser module.

I pulled out crystal and adjusted it again, glued and now power is much better and module is stable. It wasn't that hard.

Excellent workarounds there!
Flipping the lenses inside the brass holder was a good move!

Nice heatsink

I will post my 1W IR build as soon as I get rid of one anoying problem and it is fully functional!

Thank you...
I forgot to mention that Eudaimonium helped me a lot, he made this massive heatsink for me.
Thanks again.

And I really want to see AMC7135 based IR build.

i thought IR was invs? or is just the beam invs? cause i see the purplish beam

IR can be seen easily with cameras.
Different cameras show different color of IR light.

But 808nm is on very edge between visible and invisible light and you can even see it with naked eye.
It's like very dim deep red color.

My 1W IR looks like ~1-2 mW of simple red pointers...

But on cellphone cameras it is glaring white color...

Check out billg519 channel on youtube, you will see how IR lasers appear on cameras.

does anyone here know where to buy good 808nm glasses?

hey what diode did you use/whered you get it?
thanks, hugo.

It's 1W 808nm 9mm diode bought from ebay (seller: hesc_photonics)
He advertised these diodes as 2W but they are 1W.