Bare tube 594nm HeNe's?

[Chicxulub]

Are there any of these? What do they look like? What kind of duty cycle could one of these handle?

 

[LtKernelPanic]

They look like any other bare HeNe tube for the most part. Some manufactures like REO used a mostly metal tube instead of glass. Duty cycle AFAICT is pretty much infinite though I don't run mine excessively to prolong tube life as much as possible.

 

[ultimatekaiser]

bare tubes in non-red were never really produced due to the excessivly low gain and sensitivity. leaving them out in the open causes the power to be lower due to the cooling effects and air currents. They're built into the black tubes for protection, as well as to help heat distribute evenly across the tube and protect the mirror mounts from moving due to contractions in the metal. even so much as blowing on one has an effect on the power of those larger, lower gain tubes. It affects the red ones too, but alot less so, as the gain at red is alot higher. the gain of the yellow line is only something like 1/15th that of red. so its very very weak by comparison. a 12mW tube or so of red, will only do perhaps 1-2mW of yellow, and only after being optimized with different mirrors, gas ratios and pressures. else, it may not even lase at yellow at all. a bare tube in the open could very well cycle between, low or even no power at all in some cases. They look basically the same anyway, though yellow and greens do tend to have a slightly more pinkish color by a little due to the often lower pressures involved. (and thus a shorter lifespan)

edit: and HeNes have an unlimited duty cycle. they can run indefinitely until the cathode is expended.

 

[Chicxulub]

Thanks for the feedback UK. I figured there was a good reason that we don't see these and there damn sure is! Lol

 

[ultimatekaiser]

Yeah. The bare tubes are more made as replacement parts. They're not meant to be run like that. Part of why I like old side arm tubes, as they have external mirrors, and don't have this problem. But finding one working is all but impossible.

 

[Pman]

You've sure have a beautiful wavelength collection Ult Where do you store all of that? Looks like there's hardly a handheld in there.

 

[ultimatekaiser]

It certainly takes up a lot of space....And I don't have a lot of handhelds because I don't particularly care for them. Quality is more important for my use than pure power output. I can do a ton more things with a stable 10-20mW, than with 100mW that's all over the place. That and with bare parts and the know how, I can make my own stuff, or rebuild old things, rather than rely on imports from places like CNI by understanding the science behind it. The downside is that it's much more expensive... But I'm sure many of you'd agree that you get what you pay for. That and many of you already have the tools to make the same things...you just have to spend the time and money to make it happen. Explore, and be creative. :tinfoil:

I enjoy handhelds as much as the next guy... But there's tons of other possibilities as well... Don't limit yourself to just one medium. Not every laser one makes has to be able to be carried around. Good things take time to make. I feel like a lot of people here have a lot more potential than making pseudo-flashlights that burn things just because that's what's available easily.