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Thread: Mega RGB via KTP / Dye / 445... Discuss...

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    Quote Originally Posted by tocket View Post
    So you're saying the absorption spectrum of the triplet state completely overlaps its emission spectrum? I don't think that's true. There may of course be partial overlaps sometimes, but you can get that with singlet and ground state as well.
    If it wasn't true then there'd be no need for a dye jet at all, or for triplet state quenchers in the dye solution.

  2. #32
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    Quote Originally Posted by goninanbl00d View Post
    If it wasn't true then there'd be no need for a dye jet at all, or for triplet state quenchers in the dye solution.
    There are some solid dyes using polymers, but they use short pulse excitation and lower rep rates.
    In other words time to unexcite the problematic state

    Steve

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    Quote Originally Posted by mixedgas View Post
    There are some solid dyes using polymers, but they use short pulse excitation and lower rep rates.
    In other words time to unexcite the problematic state

    Steve
    Hence why a N2 pumped dye laser can get away with a 1x2cm cuvette.

    Now try pumping that with a KTP running CW, and it stops working (followed promptly by an a splode of boiling dye).

    So, technically, you don't need to flow the dye. But only if you don't mind it not being able to run faster than 10s of Hz.

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    Click image for larger version. 

Name:	BLUEDIODEDYE.pdf 
Views:	41 
Size:	580.7 KB 
ID:	21770So, technically, you don't need to flow the dye. But only if you don't mind it not being able to run faster than 10s of Hz.[/QUOTE]

    At what they had to go through to make things lase, ie DFB, thin disk, nanosecond pulsed driver, special coatings, it makes it a novelty, at best, for PLers. However there are a few lab situations that could use this scheme. I suspect lasing module lifetime is short.

    To get the rate up, use a spinning disk. Still probably not good enough, and who wants to build a custom made, very precise, 6 axis CD-ROM drive into their laser, like these folks did. Note small spot size of expensive, quality, pump laser. Thirty mW for two watts pump just is not economical, and note the cryptic "The laser extinguished itself at 3 watts",
    I imagine that was the burnout of the thin film.

    http://www.photonics.com/Article.aspx?AID=26077



    Steve
    Last edited by mixedgas; 11-30-2010 at 02:33.

  5. #35
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    Hey P'fessor -

    Quote Originally Posted by mixedgas View Post
    There is a good reason why I gave Jon bottles of Kiton Red and DCM.
    Yes, and for-that, Steve, I would dye for you.... ...Sorry... that was bad, I know...

    ...BUT, having the K-R and DCM, in themselves, doesn't help me nail the 'exact mix' that LS-uses (considering other potential quenchers / additives that I certainly-wont have...)
    and I've been too 'scaredy-cat' to risk 'worsening' the performance of what I've got... and, as you know, 'purging / refilling' such a system, just to 'play' with a mix - especially if
    it takes a few tries - ain't exactly a 'fun chore'...

    Anyhoo, seems like the best thing to do is just find one, with a 'fresher' dye-cartridge and go from there... Or, yeah, sure - hock a kidney and drop the $1250. on a new one... but where's the fun in that?...

    peas...
    j
    ....and armed only with his trusty 21 Zorgawatt KTiOPO4...

  6. #36
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    Quote Originally Posted by mixedgas View Post
    Click image for larger version. 

Name:	BLUEDIODEDYE.pdf 
Views:	41 
Size:	580.7 KB 
ID:	21770So, technically, you don't need to flow the dye. But only if you don't mind it not being able to run faster than 10s of Hz.
    At what they had to go through to make things lase, ie DFB, thin disk, nanosecond pulsed driver, special coatings, it makes it a novelty, at best, for PLers. However there are a few lab situations that could use this scheme. I suspect lasing module lifetime is short.

    To get the rate up, use a spinning disk. Still probably not good enough, and who wants to build a custom made, very precise, 6 axis CD-ROM drive into their laser, like these folks did. Note small spot size of expensive, quality, pump laser. Thirty mW for two watts pump just is not economical, and note the cryptic "The laser extinguished itself at 3 watts",
    I imagine that was the burnout of the thin film.

    http://www.photonics.com/Article.aspx?AID=26077



    Steve[/QUOTE]

    Well, technically there's no dye flow, but it still requires moving the dye around.

    It's arguably worse than using a dye jet- and certainly harder to get working.

    At this rate, it'd be significantly easier to use a DPSS or ArKr, even if you're using a proper CW system.

    Only situation where I can see dye systems being practical would be when large amounts of yellow is needed- and in most cases, there's easier ways to get the same yellow, without having to deal with dyes, all the accessories (dye circulator and spare dye), and the risk for spillage.

  7. #37
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    Jon, we have plenty of people around here with IR spectrometers, determining the mix may be easier if you attack it that way. Bribe one of our resident grad students with some nice piece of gear and have them run a KBR pellet doped with the dye mix. The test will only need a few tens of milligrams.

    I can tell you one thing. Lexel used COT in the mix at one time.I have paper saying they stopped, in a service manual.

    Let me see if I still have a Lexel Aurora manual. (Yep Lexel once made a 150 series with a dye head built in, longer then most aircraft carriers.)

    Call Sir Brian, I'm pretty sure he would have it in the Lexel Archives.

    Have you considered just calling Exciton and asking?

    Then see if a library of the university kind has a recent copy of F.P. Shaefer, Dye Lasers.

    Park a single phase 800 on my doorstep. I'll solve your problem. Hazmat suit is a extra charge.

    Found this on a Flicker page of all places:
    Quote
    he red laser dye was my own mixture of "DCM Special" which is equal parts Dicyanmethylene (DCM) and Sulforhodamine B (Kiton Red 620) dissolved in benzyl alcohol and ethylene glycol. Laser lore has it that this mixture shifts the gain maximum of the DCM to the blue and increases the maximum power. We typically ran the red laser at 633 nm (near HeNe wavelengths) but it was tunable over 80 nm or so: deep blood red to light orange.The green argon-ion laser serves as the pump energy for the dye. Its lasing medium is a 6 ft. long tube containing plasma of--what else--argon ions held in a water cooled jacket which also holds a magnetic field coil for plasma confinement. The beam consists of several laser lines, the strongest being 514 nm, 488 nm, 476 nm, and 454 nm. These fall into the strong absorption bands of the laser dye.
    End quote.


    I gotta get back to work.

    Steve
    Last edited by mixedgas; 12-01-2010 at 13:16.

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    What would be the worst case scenario if a different dye was used?

    From what I can gather, if the system was flushed out (and completely clean), another dye could be used in place of the current dye in the cartridge without any damage to the system.

    If a dye is drastically different, you may need to replace the optics. But if it's something in the same wavelength band, it should be fine.

  9. #39
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    [QUOTE=goninanbl00d;173615]What would be the worst case scenario if a different dye was used?

    From what I can gather, if the system was flushed out (and completely clean), another dye could be used in place of the current dye in the cartridge without any damage to the system.
    -------------------------------------------------------------------------
    He would need to change filters, and if the solvent is drastically different, perhaps change the o-rings to Viton. (I bet they are already Viton).

    On his one laser, the inside of the quartz cell needed some scrubbing when I saw it.

    He needs to keep the old dye.

    Disposal can be interesting. Some of the stuff can stain porcelain.

    Perhaps a minor alignment tweak, if the solvent changes, because of index issues.

    Steve

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    Quote Originally Posted by goninanbl00d View Post
    Only situation where I can see dye systems being practical would be when large amounts of yellow is needed- and in most cases, there's easier ways to get the same yellow, without having to deal with dyes, all the accessories (dye circulator and spare dye), and the risk for spillage.
    AFAIK there is no way you can make a multi-line dye laser system, right? If there was, I could envision a solid state pumped 'broadband multiline' dye laser which could be a good replacement for all those 4' glass tubes once used for display purposes, if you can see where I'm going

    IMO, an Ar-Kr whitelight is still a better bet for full colour lasers than combining a bunch of diode beams. A whitelight beam has better parameters and doesn't need colour alignment, furthermore, subtractive colour mixing through a PCAOM gives a lot prettier colours than throwing RGB together.

    However, I doubt there is a lot of research into multiline lasers at this time, since it's only really useful to have a 400nm-650nm multiline head for laser displays (show purposes). If there was one, it would give RGB diode projectors a major run for their money. Imagine a perfectly-aligned, TEM00 beam you could shoot through a PCAOM for a full rainbow of colours and still have a projector the size of your home CD player...

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