An introduction, and plea to talk me out of my first big mixed gas ion laser

[joeyhagedorn]

Hi all,

First I wanted to introduce myself. I've been a long-time laser hobbiest, lurking around the internet for years. As a child I was lucky to be surrounded by lasers. My father sold audio and lighting equipment, and occasionally would bring home equipment to play with. I remember a rainbow of HeNe lasers in my basement, and that time we had an air cooled argon laser in the back yard which was the first time I saw a beam visible in clear air.

Fast forward 10 years, bored in my dorm room in college, I started my own collection with some surplus HeNes I got cheap on eBay, and a Uniphase 2214 I've had ever since. In my spare time there, I started writing some laser show software for the Mac with some friends (we made some progress, but it was never really what we envisioned) and started building some laser galvos from scratch, following the designs of ELM Chan (which also never really worked as we had envisioned). I did succeed in some projects at that time though—I managed to hack up a copy of MAME to output asteroids to my laser projector and played on a wall, built an iTunes visualizer that output to my laser, and built some of the software that powered an art installation Nuage Vert (http://hehe.org.free.fr/hehe/texte/nv/). They were good times, but after I left school, there were decidedly fewer lasers in my life.

Fast forward 10 more years, and the laser bug is biting again. I finally bought that yellow HeNe I always wanted, last year after seeing Robert Henke's Lumière II at Gray Area in San Francisco. I also realized my ability to write software and build electronics has grown in the last ten years sufficiently to get my home built galvos actually working this time.

So that brings me to today. All of this reasonable stuff I could do, like get started on the position detector circuit, or implementing a PID controller in software to run on a microcontroller—but I'm inclined to purchase a real white light gas laser so I have 1) another project, and 2) an adventure I've long been waiting for. I know a small RGB diode setup is more practical, but I'm not just interested in the end result, but appreciating all of that obsolete engineering that made me love the magic of this super saturated collimated light in the first place.

Seems like everybody is getting rid of their ion lasers these days due to the impracticality, so I thought I could pick one up cheap. I found this Coherent I70 Spectrum on eBay(http://www.ebay.com/itm/282235359736?ul_noapp=true), and have a few days off this week so maybe I could drive down from San Francisco to pick it up. I realize the cost of the laser is likely to be the least expensive part of getting it running—I'll need a 3 phase generator, and will likely need to modify the wiring in my house to hook that up. I'll need to build a water cooler. I'll need to lean on folks around here to get the necessary manuals and know-how to align it and strike a beam. If it even works after being in storage for a few years. But isn't that what its all about?

I'm all ears if anyone wants to talk me out of it, or encourage this crazy endeavor. I'm also wondering if anyone is local to the SF Bay Area and would teach me a few things, or wants to unload an Ar/Kr system to a good home.

Thanks for reading,
—Joey

[buffo]

If you are looking for a challenge, and are seriously interested in ion lasers due to their sex appeal (!), then I would say proceed with caution. The laser you're looking at *could* be a fun project, but only if the tube is gas-intact. Otherwise, it's a waste of money. At the very least, you're going to want someone to test that tube with an oudin coil before you bid.

On the other hand, if you just want to start experimenting with lasers, you'd be far better off buying a solid state module (or several modules). They are cheaper, more reliable, and they plug into the wall. (Hint: a used 3 phase generator is going to cost a lot more than that auction's "Buy it Now" price, even if you get a deal on one, and a rotary phase converter isn't exactly cheap either, even if you build one yourself.)

Bottom line: ion lasers are very cool, but only if they are gas-intact *AND* you have ready access to enough 3 phase power to run them. Oh yeah, and don't forget about the water cooling too...

For someone just starting out, it's probably not a smart purchase. There are lots of hidden expenses involved with ion lasers that you haven't considered yet.

Sorry to be the bearer of bad news...

Adam

[Vidal Wolf]

*ION*
Dunno what to saay bout them biiig ol beasts hanging round in my shop.
I love em. I love the beam quality & colors available.
Drop me a note. I have about 6 or 7 now. that are working. I should get rid of one or two.
PM me & lets make a deal.
-Nate.

[Bradfo69]

Joey.... Nate above would be an excellent resource for you. Plan a visit!

[joeyhagedorn]

Thanks everyone for the replies and PMs. I guess I can't say I was surprised by getting a word of caution—and frankly it has opened my mind a bit to all of the other options available to me beyond this one surplus system of unknown origin from a seller that doesn't know anything about it.

It seems like there are variety of single-phase Ar/Kr options available, like an Omnichrome 643—or I could get something a bit larger like a Coherent Enterprise (though I've only seen these as Argon only configurations) to get experience with the complexities of bigger systems without dealing with 3-phase.

After years of idly reading Sam's Laser FAQ I'm excited to be on the verge of finally getting a bit more serious with with this stuff. I'm sure for all of the experienced folks here my excitement towards prospective hours of frustrating tube alignment might seem a bit crazy, but I haven't really gotten to try it yet. I know it won't be all fun and games—the cost of just electrical connectors for this kind of equipment can be staggering—but I think the reward will be worth it.

I spent some good time this week trying to force some of the atoms of my likely high-pressure JDS Uniphase 2214 laser back into the wall of the tube and looking through what optics I've got laying around. My somewhat more reasonable purchase this week was an optical power meter, which I'm sure I'll need for aligning tubes and the like in the future.

Anyway, thanks for the warm welcome, and I'll see you all around here a bit more soon.

[Eidetic]

I believe the Coherent Enterprise only has UV output, and can't be converted to visible. Might want to avoid that one.

[mixedgas]

There are a pile of Enterprise IIs out there. Most are Argon single line at 458 (Legacy "CD/DVD" Disk Mastering) Single Line Argon UV(Steroelithography) , Single Line Krypton Red (Cell Sorting) or 488 only Argon (Semi Inspection). I rarely see complete systems, and most of them are dead or just the knackered head from a system rebuild. I've never seen one that was not internal mirror, either. I just tossed a AR head a while back.
I've heard rumors of one custom all lines mixed gas Enterprise, in Germany, there was a spec for it in the sales cut sheet.

Steve

[discothefunkyhippo]

Hey Joey,

djmatt on here has some gassers for sale, but they are on the east coast and well, shipping... but he does have a couple mixed gas lasers that are working.

-Sal

[joeyhagedorn]

Thanks Sal, I'll check with djmatt to see if he's got anything that might be up my alley. Plenty of other gear purchases for me in the mean time…

I'll keep my eyes open for an Ar/Kr Enterprise II, but sounds like I'll probably never find one. Oh well, it was a thought; lots more interesting stuff to check out.