Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 22

Thread: Old LiCONix Diode Laser

  1. #11
    Join Date
    Jun 2010
    Location
    USA
    Posts
    310

    Default

    Nobody said it would be perfect, however, improvising with what I've got will be a much cheaper prototype than custom blowing a glass tube.

    I don't make the kind of money to custom blow my own tubes, or have someone else do it.

  2. #12
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    Oh really? Some people do build working visible lasers without glassblowing. www.pulslaser.de
    Just the vacuum must be extremely high and the duty cycle very low. A diffusion pump can reach the required level.
    He uses O-rings for the seals, so he can never seal off the tubes.

    Re old tubes:

    What you keep missing is there is a minimum length to have enough gain to overcome the losses. Then the collisions with the tube walls to create neutral states do matter. Too small a bore can mean the wrong type of collision for neutral gas lasers. Those HENEs you mess with have ultra ultra high Q cavities. Q is the abbreviation for quality factor. High Q cavities do support weak lines, but they also don't transmit much usable power. they also would jam up when the metal vapor hits the mirrors.

    Steve
    Last edited by mixedgas; 12-10-2013 at 17:05.
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  3. #13
    Join Date
    Jun 2010
    Location
    USA
    Posts
    310

    Default

    There's no need to be rude here.

    Yes, heat would be a problem. I am going to route of pulsing this, mostly for the high peak power.

    I'm trying to do what I can in a dorm, making use of what I've got.

    Lastly, this tube will need to be glass as a copper, or metal tube, will interact with the mercury and amalgam (amalgamate?) with the metal. So, because of this, glass will be needed. I'm sure I could find another glass tube perhaps, and repurpose it.

    I can only see what they did with the pictures, though I cannot read any of that.

    There has been work re-purposing HeNes for HeHgs, though I am currently in no mood to 1. hijack this thread, or 2. deal with that right now. It's been a long day, and I'm taking the night off.

    We can continue this later over PM, but doing this here would be a disservice to the Eidetic.
    Last edited by SoulFeast; 12-10-2013 at 17:00.

  4. #14
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    Hydragyrum does not lase in small diameter tubes.

    You can read it, copy the URL into Google translate.
    I'm not trying to be rude, I'm trying to take care of a lot of things, yet not multitask.
    Eidetic knows that.

    Some day I'll take a picture of my tube collection for you, so you can get a idea of what is what.

    If you want I can take you a picture of the quarter pound jar of technical grade Selenium powder, too

    Try to get a to get a copy of Silfvast's "Laser Fundamentals". There is one on Abbebooks cheap. He tells you how to design gas lasers with no more then high school math. It has worked examples. There is a copy on Abbebooks for next to nothing right now.

    17$ here. Priceless. I paid 136 for mine. I have to wrench it from peoples hands to get it back.

    http://www.abebooks.com/Laser-Fundam...mc-_-PLA-_-v01

    Nicely covers what you need to know.

    Steve
    Last edited by mixedgas; 12-10-2013 at 17:19.
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  5. #15
    Join Date
    Jun 2010
    Location
    USA
    Posts
    310

    Default

    Got it working, reading now.

    I bought the book.

    Considering perhaps getting a custom glass tube, just a straight glass tube 180cm long, and 12mm wide. Then doing the filing, and sanding for the b-windows, and drilling for tip-off and Hg.

    I will read that book when it arrives.
    Last edited by SoulFeast; 12-10-2013 at 17:45.

  6. #16
    Join Date
    Jun 2009
    Location
    Mesa, AZ
    Posts
    1,277

    Default

    Here are some more pics of the Liconix 501 He-Se tube. Notice the magnets stuck on it, asbestos around the cathode end, and cooling fins in front of the rear Brewster window. The magnets are there to hold onto little steel disks used to shield the windows during initial running and processing.
    Click image for larger version. 

Name:	Liconix 501 front.jpg 
Views:	6 
Size:	155.9 KB 
ID:	41219Click image for larger version. 

Name:	Liconix 501 cathode.jpg 
Views:	7 
Size:	157.6 KB 
ID:	41220Click image for larger version. 

Name:	Liconix 501 anode.jpg 
Views:	7 
Size:	180.3 KB 
ID:	41221Click image for larger version. 

Name:	Liconix 501 rear.jpg 
Views:	7 
Size:	188.5 KB 
ID:	41222Click image for larger version. 

Name:	Liconix 501 prism only.jpg 
Views:	6 
Size:	176.6 KB 
ID:	41223

    The following pics are from the second head, with its tube intact. They show the front end heat sink fins, the Se heater wrapped with asbestos, and the steel disk held near the anode. Also notice the different construction of the tube at the Se heater junction.
    Click image for larger version. 

Name:	Liconix 501 front heat sink.jpg 
Views:	4 
Size:	144.9 KB 
ID:	41224Click image for larger version. 

Name:	Liconix 501 anode disk.jpg 
Views:	6 
Size:	178.9 KB 
ID:	41226
    Last edited by Eidetic; 12-11-2013 at 05:55.

  7. #17
    Join Date
    Dec 2008
    Location
    Vezon, Belgium
    Posts
    1,017

    Default

    Eidetic,

    If interested I have two old diode laser drivers from liconix, for TO3 laser diodes, with custom circuitry

    If you have the opportunity to use them in your collection, or have access to documentation, it could be nice

    I'd like to be able to use them, or that someone uses them in a way

    I wouldn't like to strip them apart for components

    EDIT:

    I also have 3 100mW HeCd tubes of 3000, 4000 and 6000 hours sitting around, unknow state, and I want to test them

    I also thought about reverse cataphoresis to replenish cadmium reservoir, but I fear about releasing all that helium, not talking about the one I'll have to burn to get them to lase someway

    Cavities are carbon rods for what I recall, optics for blue, original intact circuitry...

    If you have any idea of what I could do with those, I'd be happy

  8. #18
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    Quote Originally Posted by SoulFeast View Post
    Got it working, reading now.

    I bought the book.

    Considering perhaps getting a custom glass tube, just a straight glass tube 180cm long, and 12mm wide. Then doing the filing, and sanding for the b-windows, and drilling for tip-off and Hg.

    I will read that book when it arrives.

    Woa Hoss, lets start with the do-able with existing resources, Shall we?

    No, your not doing that HG laser thing just yet, you'll find out why later. Because until you learn about gain per meter, trying just anything wont help you.

    Besides filing glass breaks glass. Proper glass cutting 4" diameter diamond wheels are 9-20$ and won't crack the glass. But that is a story for another day.

    Measuring gain per meter:

    Get a two Brewster tube on loan from Sam. Set up your laser that outputs the mystery orange line so it makes one pass down the two Brewster tube. Put in two pieces of crossed Polaroid so you can adjust the brightness of the source laser before its amplified. Chop the source laser beam with a chopping wheel. This lets you do coherent detection with a lock-in amplifier. If you do not chop the beam, you will find that the glow from the plasma is stronger then then laser signal, and you will not see anything. Put your prism assembly or that monochromator you bought with the PMT after the 2 Brewster tube. The AC coupled pulsed signal from the photodiode now has two components. When the source beam is blocked, the signal that is there is the plasma glow. When the source beam is unblocked, the signal that is there is the source beam, plus any amplification by the tube + the plasma glow. The lock in amplifier subtracts the plasma glow.

    If your mystery line is truly a HENE line, you will see amplification. If it is a impurity line you will not see amplification and you have something to work with. Amplification here means a few hundred thousand photons per pass, not something you would see without the magic of the Lock-In amplifier.

    This is a lot easier then trying to fit a vacuum system in a dorm. If you took Hydragyrum into your dorm, you would be up for serious punishment + the cost of remodeling the dorm. The stuff is persistent if spilled and a chronic neurotoxin if you sleep with the fumes every night. Google "Mad as a Hatter".

    Required equipment, two photodiodes with reverse bias (10$ each to build) A used lock-in from Ebay. A cheap oscilloscope from Ebay or borrowed at work, A home made chopping wheel that chops the beam at 1 KHz. A two Brewster tube (NOT FROM REO!) with power supply. (or a 1B tube and beamsplitting cubes), and a voltmeter.

    Then you would actually know what that line is without building a "Toy Train Wavemeter"

    Question of the day. Why did I specify a non-REO 2B tube?

    Silfvast's book covers gain per meter, aka "per pass gain". It also covers the losses in the tube. Gain must exceed loss, or there is no lasing. He covers the whole design thing in the book, in simple terms, with the example of designing a small HENE and a Co2.

    He also invented the whole helium based metal vapor laser family, He-Cd is his baby, so to speak.

    Steve
    Last edited by mixedgas; 12-11-2013 at 04:36.
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  9. #19
    Join Date
    Jun 2010
    Location
    USA
    Posts
    310

    Default

    So this method will result in the meter ignoring the plasma glow, and regular HeNe lines, as a sort of zero. Meaning anything foreign will be read. Correct? That is why I need to filter the output beam so much, so that it gets filtered out as being tube glow.

    Interesting. I will bring this up to Sam, though it will be a while, I already owe him, and I doubt any self-respecting person would want to let me borrow more, when I still owe.

    As far as why NOT REO. Well, logic dictates that using a REO tube would likely add a biased result as the only tubes to display this, were REO. So if it is Ar in this tube, and other REO's, I would need a pure HeNe from another manufacturer so that the mystery line is either killed if it's part of the plasma glow in the B tube, meaning a HeNe line, or sticks out, since it is from argon.

    I will need to modify this a bit, there will be a grating before the polaroids. I will need to have a way to make sure the line is in, after-all, it's not the most stable line by far...

    Sounds like the book I was looking for. Did not consider Hg contamination.. I will wait for the HeHg until I have a garage, and I will start with HeSe as my first helium-metal vapor.

    As for this HeSe, did either of them ever work while in your possession? I've only seen one working, and it was a bad quality picture of a DIY, taken in '99 or something like that. So, not the best quality.
    Last edited by SoulFeast; 12-11-2013 at 09:31.

  10. #20
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    You could use two passes through a 1B tube, depending on the rear mirror coating, this requires a beamsplitter added to the system.

    So you switch the tube off to measure the transmission losses, then you do the measurement with the plasma on.


    Steve
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •