He-Ne Laser, Uniphase 098-1

[Methelina]

Here is a little story XD

Once I has an idea to make a gas-laser. Its an expensive and a rare stuff... cuz the most common way is just to buy a CO2 laser... And this is not a my way to do things so i choosed a long way but creative one ;D


The laser tube was found:
Uniphase 098-1


Sadly HR and OC was not in a good condition...



So, the PSU prepeared with a proper (average ;D ) parametres. From an old USSR laser LG-78 (Stolen from the somewhere, :-X)



I made a little tune of it...
The scheme is pretty simple:
But the Extra in the progress



And I have made a DIY HV-wiring from a common wire, heat shrink tube and a medical LDPE-tubing for additional protection. I took the terminals from the charger for lead batteries:



And Voila! ;D
So happy to see no purple light than...
Attachment 60388

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Video of the first run:

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Lasing is pretty unstable. I blame the fatigue of the tube itself and the wrong ballast resistance.
As I found Sam's text:

This is a Uniphase model 098-1 helium-neon laser tube removed from a supermarket barcode scanner. It is in excellent condition and has been tested, producing about 1.3 mW after a 10 minute warmup. The tube requires a ballast resistance of 75K ohms, and power supply capable of 1,300 V at 3.7 to 4 mA with an 8 kV start (not included). It is 243 mm (9.6 inches) long by 26 mm (1.05 inches) in diameter. Beam diameter: .75 mm, divergence: 2.6 mR (can be improved with a positive lens), random polarization, output from anode-end of tube. I'll also toss in a set of four (4) 27.4K resistors to use for the ballast resistance (3 should be sufficient but some power supplies may be happier with 4) and a pair of plastic HeNe tube mounting brackets.

I need to review my ballast from a 100k to 75k as intended to check the better results. Hope it will help to stab lasing.

[kecked]

Good to see you are well. So many people have forgotten gas lasers. I love their quality. I think that is a hard seal laser so you likely can’t do much with the mirrors or alignment. It is possible if you just let it run for a few weeks that it may come back to life. I’ve also heard of soaking in a bag of helium but who has a spare bag of helium 3 to waste these days.

The chips don’t look to be in a place that should be a problem.

you might try to repump it but again good luck finding isotopic mixtures even if you have the pumps and can make a seal. At that time you could put flat clear mirrors on it and make an external cavity optic set. That would change the cavity length so not sure it will work. There are tons of optics on eBay. Maybe hit ebay and find another tube. That’s a lot cheaper.

Given the world I don’t think we can even ship you one but there are plenty in China and other countries.

I wish you well and know most of us out here do too. Best wishes.

[Methelina]

Good to see you are well. So many people have forgotten gas lasers. I love their quality. I think that is a hard seal laser so you likely can’t do much with the mirrors or alignment. It is possible if you just let it run for a few weeks that it may come back to life. I’ve also heard of soaking in a bag of helium but who has a spare bag of helium 3 to waste these days.

The chips don’t look to be in a place that should be a problem.

you might try to repump it but again good luck finding isotopic mixtures even if you have the pumps and can make a seal. At that time you could put flat clear mirrors on it and make an external cavity optic set. That would change the cavity length so not sure it will work. There are tons of optics on eBay. Maybe hit ebay and find another tube. That’s a lot cheaper.

Given the world I don’t think we can even ship you one but there are plenty in China and other countries.

I wish you well and know most of us out here do too. Best wishes.

Yay! Nice to see you here! Thank you for answering, hope you well too and your projects goin' awesomely!
For sad sake i have no pumps, helium 3 and tool to do a reseal and tube maintenance And surely not skilled enough to do this stuff...

And from a circumstances I can't change - I have no access to eBay, so i'm limited to local market or my friends that can find something usefull to let me use it or repair
The last idea from me to make a new PSU or remake this one to fit the tube's requirements.

[laserist]

I have no experience on this level, but I'd be concerned about a resistive connection between the clips and the tube's high voltage terminals. Perhaps arcing is causing the instability?

[kecked]

I remember something a long time ago about making an arc in the tube to clean the mirrors. I vaguely remember a Tesla coil being involved. That is a shame but you should be able to get something off Alibaba.com or such.

[Methelina]

I have no experience on this level, but I'd be concerned about a resistive connection between the clips and the tube's high voltage terminals. Perhaps arcing is causing the instability?

Ahhh, arcing where is an arcing? There is no arcs on my opinion.

I just need to make a proper output parameters of the PSU. For now it have 144k instead of needed 78k same as with the voltage. It make a lasing rippling and instability

[kecked]

Ahhh, arcing where is an arcing? There is no arcs on my opinion.

I just need to make a proper output parameters of the PSU. For now it have 144k instead of needed 78k same as with the voltage. It make a lasing rippling and instability

the idea is to use a high voltage something to get hot plasma by the window to clean it. Tesla coil for example

i feel bad as I have several just sitting here doing nothing. I’m afraid I’d get in trouble if I tried to send it.