"Homemade" 7W CO2 laser

[Hemlock_Mike]

WOW -- Rock salt windows!!! It's been years since I did that with a homemade tube.
A lot of work but rewarding. I didn't have the benefit of a HeNe to help allign the mirrors back then and the 15,000 volt PS was a terror.

I bought NaCl (unpolished) lenses and I think I still have a couple.

HMike

 

[Gryphon]

I'm trying to build my own CO2 laser from scratch. It's a slow process because I am constructing the actual tube from scratch.

Now this will be something to see op:

 

[AnselmoFanZero]

Jarrod will make it! No doubt.

 

[Cyparagon]

How easy is it to polish a salt lens, Mr. Mike?

 

[jarrod694]

Hi,

As usual, very good work!

Thanks! If the Lord is willing - and I'm praying this thing will work!

 

[jarrod694]

Thank you Jarrod.
Nice pics! But how do you wanna make a tube from scratch? Quarz-glass for the inner tube and plexi for the outer tube?
Well - I'm been experimenting with different setups. My first setup used a cold cathode fluorescent lamp tube from inside a flat screen monitor, with a clear polycarbonate tube lamp guard for the water jacket.

However, I decided to discontinue it. The tube was only 1 or 2 mm ID, and it was too hard to manage in this form. Alignment would have been far too difficult, keeping the tube perfectly straight was a problem, and the hole through which the beam would pass would have to have been too small.

Next, I started working with this larger design:

That one was made out of 2 fluorescent lamp tubes. One tube was narrower than the other one. The wider one was placed around the narrower one, and was terminated at it's ends with PVC end caps. The narrower one extended out past the ends of the wider one, and was terminated by copper electrodes. The wider tube was used to serve as the water jacket. Here is a better view:

Last night, however, I accidently broke this tube :yabbem:
So now I am beginning once again with a new design. This time I am experimenting with longer tubes. Here is another low pressure air discharge (which is what all of the previous pictures show) in a 5 foot long tube!

So my next design will use a longer tube, although shorter than the one shown in the picture above. I hope this time I can complete it without messing something else up :yh:

Would be a flowing-gas laser-tube right?

Basically, yes. But I would like to flow it slowly, or as little as possible if I can get away with it. I can't afford to 'burn' gas.

A TEA CO2 laser would be kinda cool!

Yes, it would. In fact, it would probably have higher gain than a CW laser, and might therefore be more forgiving with regards to optical quality.

 

[Hemlock_Mike]

It was long ago but as I recall, I used jewler's polish grit mixed with concentrated antifreeze -- no water -----
Polish the crystal on a flat piece of glass.
My tube is 3' long - glass in glass. PVC is too flexible as I recall. I still have that tube with flex mounts for the lenses.

HMike

 

[jarrod694]

That might be a record for smallest CO2 beam.
Where did you get that measurement from? And since when do functional mirrors have holes in them?

My first ruby laser used a hole in the silver coating on a normal mirror. With CO2 lasers, this is an easy alternative to expensive OC mirrors that are made of one of the few materials that will actually pass this wavlength. Hole-couplers are not best, but they work where better alternatives are not avaliable.

Here are my sets regarding experimental mirrors with my ruby laser:

Experimental Feedback (an ongoing project) - a set on Flickr

Glass slide experiments - a set on Flickr

You can click on any individual picture for a description which I have provided for some of these. If anyone cares to look at all of my sets, they can be found here:

Retrotech's photosets on Flickr

 

[jarrod694]

WOW -- Rock salt windows!!! It's been years since I did that with a homemade tube.
A lot of work but rewarding. I didn't have the benefit of a HeNe to help allign the mirrors back then and the 15,000 volt PS was a terror.

I bought NaCl (unpolished) lenses and I think I still have a couple.

HMike

Do you have any pictures? I want to see this. When it comes to this project, you might be a guide to the blind.

 

[jarrod694]

It was long ago but as I recall, I used jewler's polish grit mixed with concentrated antifreeze -- no water -----
Polish the crystal on a flat piece of glass.
My tube is 3' long - glass in glass. PVC is too flexible as I recall. I still have that tube with flex mounts for the lenses.

HMike

I've experimented with making my own copper mirrros.

However, I just took some craft copper and polished it with this stuff...

When using Jeweler's Rouge, however, I find that I actually scratched the copper to some degree. Is there a type of polish that will produce a brilliant mirror-sharp reflection in copper? I need to know. Making my own copper mirrors for future CO2 projects will not only be cheap and convenient, but rewarding as well.

 

[jarrod694]

Jarrod will make it! No doubt.

I'm hoping and praying. I'm sure I can use a lot of help. That's why I'm sharing my work with you guys - I'm sure you all have a lot to offer.

I'm a real amateur, as anyone will discover when browsing my flickr photos. I make nearly everything from scratch. No high-tech stuff over here. I tend to do a lot of trail and error experimentation - I have only a very basic understanding of electronics. That's one of the reasons why I use electrostatics for so much of my work: it's a technology that even I can understand :yh:

 

[Hemlock_Mike]

I was talking about polishing the rock salt window.
Real CO2 mirrors are best.

HMike

 

[jarrod694]

I was talking about polishing the rock salt window.
Real CO2 mirrors are best.

HMike

That's even better. The rock salt windows are what I bought the jeweler's rouge for in the first place. As is, my rock salt window will be a little like shining a laser pointer through a glass shower door - the output will be a mess, but it should still be relatively concentrated at a short distance, and should still be able to be focused. But yes - I would love to find a way to polish my homemade rock salt windows to a smoother surface. Any suggestions that you have will be greatly appreciated. I want to make this laser as much from scratch as possible. Too many ready made parts kill the fun for me - not to mention my budget:yh:

 

[AnselmoFanZero]

Rock-salt window...exzessive DIY I wouldnt try that, but I love the fact that there are people like our Jarrod.

I would use at least a set of CO2 mirrors ZnSe for example. Would cost a few bugs, but today I would not call them expensive anymore.

For the tubes: I would cut some aluminum-electrodes / tubes holders and use some o-rings and screws for sealing.

 

[HIMNL9]

Is there a type of polish that will produce a brilliant mirror-sharp reflection in copper?

Aluminium oxide powder ? .....

0.2 / 0,3 microns may polish very well almost any material, as the professionals uses it for gems and stones .....

Just an idea, anyway ..... don't really know how it can work on soft metals like copper .....

 

[jarrod694]

Its called a poor mans CO2 laser. Dont know about beam quality...divergence should be horrible...

You are correct: the beam divergence and overall quality will not be good. The performance will be worse as well. But for a DIY system from scratch, it's a start.