First crystal set.

[Kizdawg]

Well I got my first sets of crystals today to make a 532nm laser. I have been reading posts about this for a while so I did not have my hopes up for anything. In the end I think the results are quite good so far.. The first crystals were mounted on a small brass heatsink. This was a very tiny crystal maybe 1mmx1mm at the most but I managed to get 60ma out of it a couple times on a 250mw 808. The Larger crystals I baught were outputing over 80mw. This set is supposed to work up to 5W of 808nm with tec cooling and a good diode. Anyway's this is the start of my winter project to make a 1W+ 532nm handheld. This being my first green I was quite happy to just play arround a bit.. I may have spent a little too much on the crystal set the big one cost me 150$ but it was supposed to be brand new. I have seen used ones of the same set for 75$. The small set only cost me 15$. I ordered a 5W 808 C-mount diode with FAC lens for this build and I should see it sometime next week. I have also ordered some mounts and such to get it all fine tuned.. Here's what I got to play with tonight.

This is the small crystal 15$


$T2eC16RHJGoE9nuQfSeyBQNVCooE0g~~60_3 by Kizdawg, on Flickr


$(KGrHqF,!pMF!,pdblweBQNVCmoI2g~~60_3 by Kizdawg, on Flickr

Here is the large crystals


$T2eC16d,!ykE9s7t)+2hBQSQf62,zw~~60_3 by Kizdawg, on Flickr


$(KGrHqV,!lsF!fmK(O04BQSQf6lhWQ~~60_3 by Kizdawg, on Flickr

Here is a small vid I made playing tonight...

[flash=http://www.flickr.com/apps/video/stewart.swf?v=109786]width="400" height="300" flashvars="intl_lang=en-us&photo_secret=79d7e4d9fd&photo_id=8114868714" bgcolor="#000000" allowFullScreen="true"[/flash]

If that vid didnt work here is a link MVI_5477 | Flickr - Photo Sharing!

Anyway's I will keep updating as I get the stuff.. I am hopeing for over 1W on the large set we will see how it goes.. Any suggestions are welcome.

 

[Elyas]

1W+ green! interesting, good luck an I would love to see the finish product.
are you gonna make a custom host for it? Or use the ones that are already available?

 

[Kizdawg]

The finished product would have to go into a custom host. I dont have a design yet. I am just playing with this on the bench to start and after I know exactly what I will need to make it into a focusable handheld then I will start designing a host. There is still alot I dont know about all of this Like I am sure that my green output still has some IR light in it because I dont have a IR filter yet and then there is going to have to be some type of corection optics on the output too. I am currently searching for the lenses and filters I will need to do all this.

 

[foulmist]

Wow, Kent

niceeeeeeeeee! I would love to see the final built with the big crystal set!!! :drool::drool:

 

[Elyas]

The finished product would have to go into a custom host. I dont have a design yet. I am just playing with this on the bench to start and after I know exactly what I will need to make it into a focusable handheld then I will start designing a host. There is still alot I dont know about all of this Like I am sure that my green output still has some IR light in it because I dont have a IR filter yet and then there is going to have to be some type of corection optics on the output too. I am currently searching for the lenses and filters I will need to do all this.

nice! could I design you a host ? like a rough sketch? It will use the 26650 battery, since you will be drawing heaps of current.

 

[Laser Smith]

Your video doesn't work, you forgot the closing bracket "]" at the beginning for the flash code

I say try for 2W+. Don't you want the world's most powerful green handheld?

 

[Kizdawg]

First things first. I need to get the large crystals into a suitable heatsink and make a bench mount for all this. The large crystals came with some indium foil and instructions...

In order to use this properly you need to sandwich it with indium foil in a copper mounting.

I have some mounts coming but I am not too sure if any of them will work for this untill they arrive.

I will keep you all posted on how it goes but for now until I get it into a heatsink I wont be playing with it anymore. Apparently you can damage the crystals without the proper heatsinking even with low mw's. So I dont want to risk it.

 

[Flaminpyro]

Cool, you know once you get a full watt out of it your going to want 5 watts :crackup:

If you need any machine work done you know where I live...

 

[Fiddy]

nice video, sounds like someone is getting raped tho.

 

[Kizdawg]

I was thinking about asking you to make me a mount for these crystals Jeff...

Yes the Macaw's were goin nutz... It's like they new I was filming.. There the same when someone is on the phone.

So here is a message back from the seller about the indium foil and mount. I am waiting on another reply but I think I got the jist of this..

Foil is a special metal called indium, It is as soft as clay, but as thermally conductive as aluminum. Make a mount similar to the one shown, make sure you have small holes for laser in/out, put the foil where the crystal will go on the mount, put pin-oles in the foil for laser in/out, and sandwitch the crystal in the mount as shown. Make sure the bigger themal mass is facing the side with the bluish vanadate crystal. One customer got over 600mw TEM 00 holography grade!

I Q's back to him were should the plate that goes over the vandate be machined out to the diamond shape or if just a flat plate over the vandate with the indium would suffice. I am not too sure how large the holes should be in the mount either I guess the smaller the better. I plan on TEC cooling the base on this too so I think heat should be at a minimum. I need to find some small drivers for the tec's with temp control too. I think I can use my computers fan ports to work the benchtop each fan port has a temp sensor connection too it so I could use them to run the TEC to controle the temp of the diode and crystals.

I guess this is what I am lookin for
Correct, the indium is acting as a thermally conductive layer. The more surface of the vanadate side covered by foil the better it will lase. There is no need to cut out a diamond shape in the heat sinnk as the indium will form a mold that will secure it in place. It is best to find the sweet spot on the crystal first so you can make the hole for the pump beam as small as possible, generaly 0.5 to 1mm on the pump side and 1 to 2mm on the output side is sufficient.

 

[cheech226]

great video. pretty good results holding the crystals by hand. no oc needed? makes it look easy ;-)

 

[Flaminpyro]

So am I reading this correctly, you should completely cover the xtal with the indium foil and have a small hole in the foil on the input and output side of the xtal :thinking:

How about a holder where the xtal sits in a copper saddle (TEC cooled) and a second spring loaded saddle comes down on top of the xtal to hold it in place with indium foil lining both saddles.

BTW when I first seen the title I though you were messing around with an early model radio :crackup:
I do remember my first xtal set I was about 8 years old.

 

[Kizdawg]

I believe that was all built in. This item for sale is a high power optically contacted green laser monolithic crystal. I had asked him if I needed the oc and he told me I didnt. But I was not sure untill i tried it. The small one is the same it's just alot harder to hit the 808 on the crystal because it is so small. Nice big target on the larger set!

Jeff that sounds just like what I need. This whole thing is going to have to be TEC cooled if I have a hope to get 1W The 5W diode takes 5A and will cause alot of heat I am sure. I am not too sure what kind of mount I can get for the cmount diode but something will have to be able to be virtically alligned. either the crystal or the diode.

 

[cheech226]

i'm thinking a b+w 473 pump might do right with that large crystal set. it has all the correction optics/tecs for the 808.

 

[Kizdawg]

Ya lost me there cheech

 

[Flaminpyro]

He means something like this>100mW Blue 473nm ND YVO4 YAG Laser Resonator Optic Crystal Assembly Tec Mount | eBay

I'm just not sure it would be good up to 5W...