Yellow HeNe 594nm on Ebay

Dear Laserfriends

just saw on ebay a yellow HeNe for US$200, maybe someone is interested. Please note, this is not my offer, so I don't guarantee for anything at all. Seems there is no power supply with it, but this should be easily found or self-made.

Research Electro Optics Lhyr 0250M Class IIIA Helium Neon Laser | eBay

For me it's not an option to buy that one. I live in Switzerland and it would be too expensive to ship. Besides that, I already have a yellow HeNe in my small laser collection ;-)

Best regards and good-luck
argon

yeah I saw that one. I wonder if it still works...

Yellows pop up fairly often. I'm still waiting for a 612nm to complete my HeNe collection.

They pop up on surplus, Yes. But they're going out of manufacture. Everyone except for Newport has removed them from their catalog. They're about 2 grand for 1-2mW and dpss yellow at <5mW is now about the same price, (about $1800) and are both more efficient and smaller. They're also less fragile...so they're disappearing now, as they're now basically obsolete.

ultimatekaiser said:

They pop up on surplus, Yes. But they're going out of manufacture. Everyone except for Newport has removed them from their catalog. They're about 2 grand for 1-2mW and dpss yellow at <5mW is now about the same price, (about $1800) and are both more efficient and smaller. They're also less fragile...so they're disappearing now, as they're now basically obsolete.

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I guess I should really try to find some sometime soon if I want to have a decent HeNe collection. All of mine are 633nm since I'm a bit too cheap to buy up the other colors. :undecided:

Are all HeNes on their way out? It doesn't seem like there are any wavelengths that haven't been replaced by DPSS or direct diodes. Argons definitely seem to be yielding to their replacements. Even CO2s seem to be falling out of industrial favor pretty rapidly for higher power diodes and fiber lasers.

Gas in general is obsolete in alot of applications. Ion lasers in particular are hit hard by newer technologies. Even CO2, which is still quite useful in various areas, is definitely losing some steam to certain alternatives in various places. I do feel that HeNe lasers however, or at least red ones, will always have their place, especially in education. They're a great low-cost (relatively speaking) solution to a lot of basic laser problems, and give a very good beam for their cost. especially at surplus prices....and they are very useful for teaching laser principles. Even now though, in a lot of sensitive applications, they've already been replaced as well. Semiconductors are the way of the future, even for lasers....gas is just too expensive to maintain and build - especially in large quantities, compared to tiny diodes. But even gas isn't completely gone from some research areas. They'll be around for a long while, just in small numbers for niche things that require them. They're just not as practical and general use as they once were with the advent of newer technologies. Kinda like short-arc lamps being replaced by LEDs and other types of lighting. They still have their uses, but are not used in every single thing anymore.

I guess there's still a chance that for a short period after the commercial and scientific markets for gas lasers effectively dissappear, we could have a great surplus market on our hands.

Rivem said:

I guess I should really try to find some sometime soon if I want to have a decent HeNe collection. All of mine are 633nm since I'm a bit too cheap to buy up the other colors. :undecided:

Are all HeNes on their way out? It doesn't seem like there are any wavelengths that haven't been replaced by DPSS or direct diodes. Argons definitely seem to be yielding to their replacements. Even CO2s seem to be falling out of industrial favor pretty rapidly for higher power diodes and fiber lasers.

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Yep, as UK said, gas in general is on its way out.

It's a shame, too. Gas was the first CW lasing medium, so it will always have its place in history, but eventually gas lasers will become so obsolete that they won't even show up on the surplus market very often, due to their fragility and a lack of new units being manufactured.

If you want to get into gas, I'd recommend doing it ASAP. I've already noticed a decrease in available units. I've been looking for a Lasos argon for over 6 months, and haven't found a single unit.

Gas can still provide things that other mediums don't, such as HeSe, which lases on something like 24 visible lines.

Yes it's rather unfortunate but it also kind of makes sense as they don't last very long and are extremely expensive. Selenium is a great metal but it never really took off. Metal vapor lasers in general have always been a pain in the ass...cadmium was the only really important and viable one commercially, and anyone familiar with gas knows how complex, expensive, temperamental, and fragile they are. They've always just been an interim solution until solid state came down in cost.

Many thanks for all your inputs ;-)
I agree with what's been said about gas lasers, but: HeNes have a way better beam quality than most dpss lasers and the lifetime of a HeNe can exceed 20000 hours! I would like to see a solid state laser with that lifetime. HeNe is still present in laboratories all over the world. Unfortunately I have to agree with argons and other types of gas lasers, they really disappear fast and prices are getting higher and higher.

Best regards
argon

argon said:

Many thanks for all your inputs ;-)
I agree with what's been said about gas lasers, but: HeNes have a way better beam quality than most dpss lasers and the lifetime of a HeNe can exceed 20000 hours! I would like to see a solid state laser with that lifetime. HeNe is still present in laboratories all over the world. Unfortunately I have to agree with argons and other types of gas lasers, they really disappear fast and prices are getting higher and higher.

Best regards
argon

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This simply isn't true. I do agree they have good beam profiles. But diode and DPSS can be stabilized to get far lower noise and higher stability than HeNes. It's just substantially more expensive. Most HeNes are rated for 10k hours, though some spectra physics ones are rated for 5K. The only one rated for 20K is the model 127, because it has an extended cathode. Most diodes are rated for 10K, but if well cooled and well made, they can last anywhere from 10K to 40K hours. The key for HeNes is that they have good beams relative to the cost. They're inexpensive (1-2K typically) and that's their appeal vs a stabilized diode laser being in excess of 6K-10K or more.

Most diodes are rated for 10K, but if well cooled and well made, they can last anywhere from 10K to 40K hours.

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Definitely not. You could divide by ten and you're even too high, sorry ;-)

Unfortunately, most of the diode lasers even do not reach anything near 5000h. Some of them may be rated for something like that, but in reality they never reach it, not even close. If you don't believe it, ask the people who are maintaining show lasers and CD-Players. The diode laser of a CD-Player is almost everytime the very first failure. Believe me, 5000h or even more for a diode laser ist not realistic, especially not for high-powered ones. Every semiconductor material has a limited lifetime. Of course it depends mostly on the power it is driven with (actually it is the temperature, but more power means always higher temperatures), and specs of the manufacturers are mostly given as good as possible because the lasers should be selled ;-) This means, power specs are always compromised with lifetime.

Sam's LaserFAQ even says for that:

Life expectancy and warranty: Sometimes there will be a spec like "2,000 hour lifetime". This is probably mostly relevant for the expensive green DPSS laser pointers and may be reasonable. Certainly, anything over 1,000 hours is adequate for a pointer used as a pointer within one's (human) lifetime (or until it becomes obsolete). However, any lifetime claim isn't of much value unless there is an enforceable warranty!

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Source: Sam's Laser FAQ - Diode Lasers

Very good HeNe's really reach 20000h, and that is unbeaten by any other common laser.

Again Sam's LaserFAQ:

In comparison, a modern 1 mW internal mirror HeNe laser tube can be less than 150 mm (6 inches) in total length, may be powered by a solid state inverter the size of half a stick of butter, and will last more than 20,000 hours without any maintenance or a noticeable change in its performance characteristics.

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Source: http://www.repairfaq.org/sam/laserhen.htm#henhlt

and:

The operating lifetime of a typical HeNe laser tube is greater than 15,000 hours when used within its specified ratings (operating current, proper polarity, and not continuously restarting). Under these conditions, end-of-life occurs when the oxide "pickling" layer of the cathode can gets depleted. Larger diameter (1.5 or 2 inch) tubes last the longest - up to 50,000 hours or more. Small diameter (0.75 or 1 inch) tubes have the shortest lifetime - 10,000 hours or so. Since even 10,000 hours is still very long - over 1 year of continuous operation - HeNe laser lifetime is not a major consideration for most hobbyist applications. Chances are that even a surplus laser will still have thousands of hours of life remaining.

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Source: http://www.repairfaq.org/sam/laserhen.htm

Best regards
argon

argon said:

Definitely not. You could divide by ten and you're even too high, sorry ;-)

Unfortunately, most of the diode lasers even do not reach anything near 5000h. Some of them may be rated for something like that, but in reality they never reach it, not even close. If you don't believe it, ask the people who are maintaining show lasers and CD-Players. The diode laser of a CD-Player is almost everytime the very first failure. Believe me, 5000h or even more for a diode laser ist not realistic, especially not for high-powered ones. Every semiconductor material has a limited lifetime. Of course it depends mostly on the power it is driven with (actually it is the temperature, but more power means always higher temperatures), and specs of the manufacturers are mostly given as good as possible because the lasers should be selled ;-) This means, power specs are always compromised with lifetime.

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Diode lifetime depends greatly on intended use and temperature. diodes in typical use are not made to the same standard as lab diodes, and they are not cooled or protected in any way for starters. so they do tend to have short lives. Diodes made for scientific use and that are cooled to operating temperature (usually ~20C/68F) generally last incredibly long times-well beyond 10K. I have several that are well past the 10K mark (though exact count unknown as they're the old marked-wire timers and they've over-spooled on the 10K side) and are only now starting to get weak, including my D3 which is from the mid 90s. Show lasers and many other lasers are generally run warmer (~25-30C or even higher sometimes) and at much higher current levels and tend to burn up quite fast due to being modulated in a non constant way, which causes thermal shock on the tiny emitter. For every degree they rise, their lifetime is typically shortened significantly. As you stated, its a strong function of temperature and operating current. I've read several papers on this subject, sadly I'd have to go track them down as they're not all handy atm. Manufacturers dont just make stuff up. if they didn't last a long time, fiber optic wouldn't be practical...some of those emitters last several tens of thousands of hours. Also consider that not all units are the same, some last longer than others just by pure chance too.

argon said:

Sam's LaserFAQ even says for that:

Source: Sam's Laser FAQ - Diode Lasers

Very good HeNe's really reach 20000h, and that is unbeaten by any other common laser.

Again Sam's LaserFAQ:

Source: Sam's Laser FAQ - Helium-Neon Lasers

and:

Source: Sam's Laser FAQ - Helium-Neon Lasers

Best regards
argon

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I didn't deny that they could reach higher, but they are spec'd for 10K MTBF, as per pretty much every spec sheet out there - and as most don't have an hour meter, its hard to prove how long they run. I have some that look quite messy even after minimal running, and others that are sparkling from the same amount of time. No two tubes are identical, and trust me I know a lot about HeNe aging, as I have tons of them all in different states of life, as well as several unfinished, and several I'm re-gassing from leakage. I've talked with people who used to make them, and even made a few myself. I'd wager many reach 15k, but honestly, if they're run only for short times here and there, they can last nearly forever - pretty much indeterminate amounts of time. I have some from the 70s and 80s that still work, and sam has a few from the 60s that still barely run!

ultimately it still is a moot point though, as it still boils down to one thing I mentioned before: They're a great beam for the cost. and none of this disproves my statement about stability. Ultimately they cannot reach the same levels of stability as a diode laser without being incredibly tiny, and thus virtually no power output. Stabilized HeNes are limited in size, thus cannot go beyond low powers, depending on the stabilizing method. If gas was better, things like the Coherent Verdi wouldn't exist.

H2Oxide,

Have fun finding a Lasos

They are very cool, but like you i'm always on the lookout for another.

I love my collection!

argon said:

Dear Laserfriends

just saw on ebay a yellow HeNe for US$200, maybe someone is interested. Please note, this is not my offer, so I don't guarantee for anything at all. Seems there is no power supply with it, but this should be easily found or self-made.

Research Electro Optics Lhyr 0250M Class IIIA Helium Neon Laser | eBay

For me it's not an option to buy that one. I live in Switzerland and it would be too expensive to ship. Besides that, I already have a yellow HeNe in my small laser collection ;-)

Best regards and good-luck
argon

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What's up with the input voltage 115v?

I'm guessing the PSU it came with originally was a mains voltage supply. Off the top of my head that tube should use like 2750VDC @ 6.5mA.