Want to build 1W 808nm laser - help please

[LuxorLasers147]

Hey all :wave:

I know little about IR diodes, but since these 1W 808 came out, i always wanted to build green laser, in flashlight if possible.

I´ve just a few questions regarding the diode, the focusing lens and the "crystals" to convert to green light.

So..

- Wheres the cheapest place to get a 1W 808 diode?

- What lens should i get for the module.

- How do i mount the brass holder containning the crystals? Can i just glue it right on the finger grip where the light comes out? Or does it need to be at the right distance?

Need some help here :undecided:

thanks

 

[Foshizzle45]

Double post :tsk:

 

[rhd]

Here's the bottom line of what everyone is going to tell you here:

1) You won't be able to build your own DPSS green laser.

2) The actual green you'd get from 1W of 808nm input wouldn't be worth the cost of doing it yourself anyway.

3) Again, you won't be able to build your own DPSS green laser.

 

[LuxorLasers147]

Double post :tsk:

Ups, my bad

Here's the bottom line of what everyone is going to tell you here:

1) You won't be able to build your own DPSS green laser.

2) The actual green you'd get from 1W of 808nm input wouldn't be worth the cost of doing it yourself anyway.

3) Again, you won't be able to build your own DPSS green laser.

Ok... i just thought it could be able to do something like this:

Homemade 532nm Green Laser - YouTube

I really dont think this is that hard to make. why you say that?

 

[Bluefan]

It really is that simple. If you have a hybrid crystal set you only need to focus the pump beam in the crystal. In most pointers the pump laser is just placed very close to the crystal set without any lens and that works fine too. Surprisingly a "200mW" pointer from priceangles which gave only 80mW had a smaller crystal set than a 5mW ebay pointer. I took the crystal set from the 5mW pointer and put a 1W diode close to it. I didn't turn up the current all the way the diode could take, but I easily got 60mW. It's not that hard.

 

[rhd]

It really is that simple. If you have a hybrid crystal set you only need to focus the pump beam in the crystal. In most pointers the pump laser is just placed very close to the crystal set without any lens and that works fine too. Surprisingly a "200mW" pointer from priceangles which gave only 80mW had a smaller crystal set than a 5mW ebay pointer. I took the crystal set from the 5mW pointer and put a 1W diode close to it. I didn't turn up the current all the way the diode could take, but I easily got 60mW. It's not that hard.

Lol, well in that case, you're not so much building your own 532nm, as you are "reassembling" the pieces of one that was already built.

Still, I struggle to imagine how you'd get any more output than the most powerful 532nm laser that you harvested for the parts to "make your own".

 

[LuxorLasers147]

Lol, well in that case, you're not so much building your own 532nm, as you are "reassembling" the pieces of one that was already built.

Still, I struggle to imagine how you'd get any more output than the most powerful 532nm laser that you harvested for the parts to "make your own".

Whatever, I just wanted to replicate what i saw on that video . I just didnt know that the output was affected that much.

It really is that simple. If you have a hybrid crystal set you only need to focus the pump beam in the crystal. In most pointers the pump laser is just placed very close to the crystal set without any lens and that works fine too. Surprisingly a "200mW" pointer from priceangles which gave only 80mW had a smaller crystal set than a 5mW ebay pointer. I took the crystal set from the 5mW pointer and put a 1W diode close to it. I didn't turn up the current all the way the diode could take, but I easily got 60mW. It's not that hard.

Lol only 60mW xD. What takes to reach 200mW, a 10A diode? haha

 

[Bluefan]

I didn't turn up the current to 1W of output, maybe I didn't even reach 500mW of output to get above 60mW.

 

[honeyx]

I also got green modules fixed by replacing the leded ir diode with a 1W 808nm diode. Just had to decan the new diode, drill a bit bigger hole into the brass so the saddle of the diode cristal passes through and realign the KTP. Non of the diodes were driven at their max, but depending to their quality I got either the same output like before or at least some mW below.

The last module I fixed this way was a 200mW one. Got 140mW out of it after the fix. Could be even more if the diode would be cooled down enough to hit exactly 808nm.

With most of the 1W 808nm 9mm laserdiodes it´s a bit of lottery you get a good one. Some do 805nm others do 810nm and your results wont be that impressive. Therefore I´m always checking them to which one gives me the best output bafore I´m going to decan it.

Thats also why there are a lot of cheap underspec green lasers on the marked. Most of them are using cheap ir diodes that don´t do exactly 808nm but just something near 808nm. Or they use a low quality cristal set or it´s not aligned well. Or of course all together.

However. Building your own green or repairing an existing module will be a hard task, but a great challange. It´s simply learning by doing. Simply try it. The worst you can do is to fail. If you don´t try it you already failed. But if you succeed your award will be a working green laser.


Btw. If you want to know where to get the Ir diodes cheap. PM me. You don´t need a lens. Just put the KTP cristal as close as you can to the ir laser cristal. The closer it is the more green you will get. After realigning you simply can glue it with superglue but have to make sure it doesn´t move while apliyng a tip of superglue. It´s not a good idea to glue it on the diodes can as the distance between the cristals will be to big so you will loose a lot of power. The same with using lenses to focus it. You will be able to focus the IR but you will loose a lot of it while passing the lenses.

So the best way to get as much power of it as much you can is to decan the diode and to reduce the distance between the cristals to a minimum.

Lol only 60mW xD. What takes to reach 200mW, a 10A diode? haha

Remember. He used a 5mW cristal set and got 60mW out of it. The ralation is something between 5~7 to 1. Meaning 5~7mW IR is giving 1mW green, so the diode he used obviously was set to about 300-400mA.

 

[Bluefan]

Note that the crystal you mention isn't just the KTP, it's a hybrid crystal with a Nd:YAG or Nd:YVO crystal glued to a KTP crystal and both crystals are coated.

I actually found that the diode shouldn't be as close as possible to the crystal, if the focus has a good voerlap with the cavity mode it has a higher efficiency. I found the highest power with a slight gap (a fraction of a mm) between the crystal set and the diode.

I heard superglue would release gasses that can degrade coatings, so some form of epoxy would be better, but I have no experience with this.

 

[honeyx]

I found the highest power with a slight gap (a fraction of a mm) between the crystal set and the diode.

Thats what I meant by saying as close as possible. Just as close till it´s just a fraction of a mm. The cristals anyway shouldn´t touch each other. A single touch could damage the coatings on either the diode´s cristal or the Nd:YAG.

I heard superglue would release gasses that can degrade coatings, so some form of epoxy would be better, but I have no experience with this.

You are right. It´s the cyanoacrylate that turns into a kind of gas and covers cold surfaces around the glue. I found it doesn´t do that if the surface is warmed up. Therefore I´m always keeping the parts that have to be glued together above roomtemp till the glue hardens. This can be done for example by powering the diode on for a short while till the brass gets warm. Also am just using a little drop of it to get the KTP fixed at it´s position. Afterwards you still can use some kind of epoxy.