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Thread: Hot Ice

  1. #1
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    Default Hot Ice

    You know the old saying, "what goes around comes around"? I was perusing the literature on dye lasers (what else?) and I came across this article. Who would have thought they would still be doing useful research over there?

    http://www.academia.edu/8365084/Theo...h6G_in_Acetone

    I'm really interested to know what happens when you take it a step further. I'm thinking at least ethanol, but better yet, difloromethane or Fluoroform. Solid state lasers benefit in all kinds of ways from cooling:

    https://www.youtube.com/watch?v=r6T7S3sqH3w

    Interestingly the company no longer has their own video description of this system posted.

    Of course this reminds me of:
    https://www.youtube.com/watch?v=0ds0wYpc1eM
    Last edited by planters; 06-16-2015 at 21:18.

  2. #2
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    Default



    R U thinking of using nubigblu as a cheap pump?

    I thought blue just went straight thru Rh6G

    Or is this just a temporal coincidence

    Cheers

  3. #3
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    It is just that I have so many irons in the fire.

    You are correct about RG6, however I have discovered that converter dyes if well chosen allow you do directly (electronically vs optically) pump a dye such as RG6 mixed with a down converter such as Coumarin with light at the absorption peak of the converter.

    However, I'm really into flashlamp pumped dye lasers because unlike YAG lasers, the dye laser has such a short lifetime that there is essentially no energy storage. The lamps are everything.. If the lamps could be made powerful enough then the conversion efficiency might reach 50%. But, that has never been done. If the pump chamber was constructed to have near unity coupling and very, very high reflectance above 99% then the thermodynamic limit that prevents you from producing a target flux on the dye cell greater than the emission flux of a black body (flash lamp) can be exceeded. Lasers can do this with ease. In such a case, record conversion efficiencies, approcing those with laser pumps, could be achieved.

    Cryogenic dye lasers will almost certainly have longer singlet lifetimes and this will ease the required pumping intensities. Improved fluorescence efficiencies will only hep further and finally the relative wavelengths of the singlet emission and the triplet absorption may improve. On the other hand,they could worsen. Don't know.

  4. #4
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
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    Coherent, INC provided quite a few Technical Advisors for Real G. Credits are given in the back of the movie. Hence it's realism.

    Steve
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  5. #5
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    I remember you saying that in an earlier post and I agree that it shows. A typical film maker would not have covered this with so insightful a depiction of a real laser lab.

    What I am discovering is that this may have been nearly spot on. "Freezing" an excited state is not quite right. But think about all the recent work on solid state dye lasers and PMM hosts. The whole idea is to make all the advantages of dye lasers more convenient as in lower thermal lensing and... it won't leak. But what happens if you take all the advantages of a fluid laser, it easily conforms to a given containment vessel, it is easy to incorporate converters and quenchers. All you do is add a few drops here and there. Then, at very low temperatures dR/dT decreases, lifetimes increase, line widths narrow and quantum efficiency increases. As the temperature really drops which may be possible to below LN2 temps with polar, freon solvents, what if lifetimes of the singlet state extend so much that it becomes "frozen" to usec or beyond? I think this could be real genius.

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