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Thread: My first of A Million questions

  1. #21
    Join Date
    Jul 2008
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    Marysville, WA
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    855

    Default

    what did you use to single out the lines on your argon laser?

    I've been looking for some good line filters (on the cheap) for a while now. Especially for the 457nm line! I already have a nice one here from a medical setup for the 514.5nm line.

    oh... And what model HeNe is that? I'd kill for a big HeNe...



  2. #22
    Join Date
    Nov 2008
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    14

    Question

    Quote Originally Posted by GooeyGus View Post
    what did you use to single out the lines on your argon laser?

    Dichroic beam splitters. Search on ebay, there is a guy that has all kinds.

    I've been looking for some good line filters (on the cheap) for a while now. Especially for the 457nm line! I already have a nice one here from a medical setup for the 514.5nm line.

    oh... And what model HeNe is that? I'd kill for a big HeNe...
    Thats my new baby!
    A Spectra Physics 127 35Mw massive HeNe I won it on ebay last month for $200! All it needed was a new power supply, which I built.
    Nothing else is wrong with it and is putting out a little over 35Mw right now.
    I have holography plans in the future for this beast.

    So here is some latest tests from my setup as you can see in the green circle, there is something wrong.. Suggestions welcome. First one is 20K next is 16k both 8 degree scan angle.
    Using scanpro 20K scanners, soundcard DAC, correcting amp, and LaserBoy. I may have to tune the galvos if I rule out other things, but unfortunately I have no docs.
    http://billyname.com/sandbox/Ilda22Ksmall.jpg
    http://billyname.com/sandbox/Ilda16Ksmall.jpg

    Oh and Mixedgas, I put an AO on that lens bracket I talked about, and the beam is much, much cleaner. I still dont think im getting %50 into the first order but I left well enough alone because it is Soooooooo tricky and tedious to align that dam thing. It took me a frustrating hour to get it this good.. I see I'm gunna need a precision stage or something for each AO if I decide to go this route.


    Aceman

  3. #23
    Join Date
    Oct 2006
    Location
    Central Florida
    Posts
    7,067

    Thumbs up

    Actually, for what you are working with that isn't bad at all. You may want to work in the scanners. Take a picture of the scanner amps and we can tell you what pots are what.

  4. #24
    Join Date
    Nov 2008
    Posts
    14

    Laser Warning Scanner Amp

    Thanks in advance. Here it is:
    http://billyname.com/sandbox/scan_amp.jpg

  5. #25
    Join Date
    Oct 2006
    Location
    Central Florida
    Posts
    7,067

    Post

    http://www.lasershowparts.com/files/...SCANPRO20I.pdf

    Potentiometer description
    :
    PR1: Position scale (input gain, image size adjustment)
    PR2: Low frequency damping
    PR3: Servo gain
    PR4: High frequency damping

    PR5: Position offset (
    adjusted only in factory)

  6. #26
    Join Date
    Jul 2008
    Location
    Marysville, WA
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    So rather than using a line filter to single out the 457 line and then putting it onto the dichro, you're just using the dichro itself to filter out the blue line(s) and bounce the green?

    It sounds so simple now... sometimes I think outside of the box a little too much and tend to skip over the easiest solution

  7. #27
    Join Date
    Nov 2008
    Posts
    14

    Thumbs up Scaners and stuff

    Quote Originally Posted by allthatwhichis View Post
    http://www.lasershowparts.com/files/...SCANPRO20I.pdf

    Potentiometer description
    :
    PR1: Position scale (input gain, image size adjustment)
    PR2: Low frequency damping
    PR3: Servo gain
    PR4: High frequency damping

    PR5: Position offset (
    adjusted only in factory)
    Thanks for the info. I am not going to try it yet, but when I do will you talk me through it? I seem to remember reading somewhere there is like a procedure you should use?
    Anyrate.. I think I fixed most of it. Its that dam bread board. Loose connections, stray capacitance, and noise, causes gremlins..
    Look at the signals below:

    INPUT TO MY AMP:


    OUTPUT FROM MY AMP:


    What a mess.. Notice that the flat part of that wave is slanted.
    I have since improved on this.
    So I think once I go to copper, and box up my amp board, most of this will go away.

  8. #28
    Join Date
    Nov 2008
    Posts
    14

    Default

    Quote Originally Posted by GooeyGus View Post
    So rather than using a line filter to single out the 457 line and then putting it onto the dichro, you're just using the dichro itself to filter out the blue line(s) and bounce the green?

    It sounds so simple now... sometimes I think outside of the box a little too much and tend to skip over the easiest solution
    Let see if I can explain this without a resorting to a diagram..

    HeNe beam comes out - goes to red AOM then to a dichro that passes greeen/blue and reflects red. -- to the galvos

    Argon lines go through a dichro. 458 blue goes through to the blue AOM then to a dichro that passes green but reflects blue. -- to the galvos.

    The reflection from the bluepass dichro go over to a mirror. (actually 2)
    and then I used to go through a 515 green dichro but I just dump the rest of the lines (overall makes everything brighter is seems) to the green AOM off a normal mirror then to the galvos..
    That big HeNe is so friken bright I have to attenuate my red channel to get a good white balance.


    Ok im tired now..
    Humm a picture would have been better.

    Aceman

  9. #29
    Join Date
    Oct 2006
    Location
    Cleveland, Ohio
    Posts
    2,342

    Default

    Quote Originally Posted by aceman500 View Post
    Thanks for the info. I am not going to try it yet, but when I do will you talk me through it? I seem to remember reading somewhere there is like a procedure you should use?
    Anyrate.. I think I fixed most of it. Its that dam bread board. Loose connections, stray capacitance, and noise, causes gremlins..
    Look at the signals below:

    INPUT TO MY AMP:


    OUTPUT FROM MY AMP:


    What a mess.. Notice that the flat part of that wave is slanted.
    I have since improved on this.
    So I think once I go to copper, and box up my amp board, most of this will go away.
    Looks like you have overshoot and small signal response issues. What op amps are you using, and are they decoupled?

  10. #30
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,446

    Smile

    Aceman;

    Based on the latest picture you posted of the ILDA test pattern, it appears that your scanners have either too much low frequency damping or not enough high frequency damping. You've got some serious undershoot on the corners of the center square. This is also what is causing the right edge of the lines below the square to curve upwards.

    Once you get your correction amp sorted out, I suggest you try tuning your scanners. I think you can get them dialed in much better than they are right now.

    Adam

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