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Thread: Laser light outside of the visible spectrum

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    Default Laser light outside of the visible spectrum

    Can laser light be produced at the ultraviolet end of the spectrum? I was thinking of a UV laser that projects onto a surface that fluoresces. There is paint available that is white under normal visible spectrum light but glows a colour under UV. This way there would be no beams visible, only the projected image.

    Or am I a numpty?

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    Quote Originally Posted by tendril View Post
    Can laser light be produced at the ultraviolet end of the spectrum? I was thinking of a UV laser that projects onto a surface that fluoresces. There is paint available that is white under normal visible spectrum light but glows a colour under UV. This way there would be no beams visible, only the projected image.

    Or am I a numpty?
    No, you're not a numpty at all

    Take a look here...

    http://www.lexellaser.com/techinfo_wavelengths.htm

    You can see that wavelengths in the UV region are shown to 193nm (not at all good for your eyes, causes cataracts )

    At the last UK meet Rob (aka Stanwax) was wearing a tee shirt that had been 'dyed' with a UV sensitive dye. He had a small handheld (visible) UV laser that when pointed at the shirt left a fluorescent trail wherever it struck. It loked pretty cool!

    Cheers

    Jem
    Quote: "There is a theory which states that if ever, for any reason, anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.”... Douglas Adams 1952 - 2001

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    Quote Originally Posted by Jem View Post

    You can see that wavelengths in the UV region are shown to 193nm (not at all good for your eyes, causes cataracts )


    Thought that would be the case. The intention was for a projection above eye level so there would be no chance of stray beams.

    By the looks of that link though, UV lasers are gonna be wallet bustin'


    Is it possible to halve the wavelength of a laser optically? 532nm/2 = 266nm

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    Quote Originally Posted by tendril View Post
    Is it possible to halve the wavelength of a laser optically? 532nm/2 = 266nm
    532 is already derived from 1064nm (frequency doubled), oh, and you wouldn't have to look directly at a beam in the UV wavelength, any stray reflections would be bad.

    Jem
    Quote: "There is a theory which states that if ever, for any reason, anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.”... Douglas Adams 1952 - 2001

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    Is it possible to halve the wavelength of a laser optically? 532nm/2 = 266nm
    Yes, we can do that, using the nonlinear crystal(always BBO), you can SHG (second harmonic generation) of 532nm to 266nm, always we call this is the FHG(Fourth harmonic generation) of 1064nm, for do this, we really need high peak power to increase the efficiency, as the FHG coefficient is very very small. so always this unit is Q-switch lasers,also can do CW power, but it power not very high, maybe you can check coherent company web, their "Azure 266 " is really CW working, but prices, prices is not cheaper , you know, .
    Best regards!
    Bridge
    Laser-wave can supply:
    Green 532nm, 4W, 10W, 15W
    blue 445nm, 2W, 3.5W, 6W, 10W
    blue 462nm, 2W
    Red 638nm, 500mW, 1W,2W, 4W, 5W, 6W, 8W, 10W
    All diodes, All optics, All mount, All laser base and housing for yourselves building lasers.
    Speical products, 532nm, OEM-V-SS, 4W, 98mm*46mm*48mm; OEM-H, 10W, 250mm*88mm*70mm
    www.laser-wave.com or www.laser-wave.net
    bridge@laser-wave.com or 463366312@qq.com
    We Chat: 463366312, Laserwave-Bridge

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    Quote Originally Posted by bridge View Post
    Yes, we can do that, using the nonlinear crystal(always BBO), you can SHG (second harmonic generation) of 532nm to 266nm, always we call this is the FHG(Fourth harmonic generation) of 1064nm, for do this, we really need high peak power to increase the efficiency, as the FHG coefficient is very very small. so always this unit is Q-switch lasers,also can do CW power, but it power not very high, maybe you can check coherent company web, their "Azure 266 " is really CW working, but prices, prices is not cheaper , you know, .
    Best regards!
    Bridge
    Wow Bridge... thank you for such a comprehensive explanation.

    Yes, it looks like the solution will be expensive. Still, the final power of the laser need not be high; it is the projection that is important, not the beams. Also I don't think fluorescent paint needs a high UV input to activate (somebody correct me if I'm wrong on this please) so maybe a final output of less than 30mw would suffice.

    This may also improve the safety aspect of projecting a UV laser. I am imagining an application such as projecting onto a ceiling painted with UV reactive paint.... well out of direct eyesight.


    The more I think about this, the more my brain fizzez

    Theoretical idea:

    If one made a giant flat panel with clusters of red, green and blue dots painted in fluorescent paint (sort of like a crt screen when you look at it really closely) and then scanned a UV laser across it just like an electron beam in a crt..... could you modulate the beam to produce a picture in a similar way to a crt

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    Quote Originally Posted by tendril View Post
    Wow Bridge... thank you for such a comprehensive explanation.

    Yes, it looks like the solution will be expensive. Still, the final power of the laser need not be high; it is the projection that is important, not the beams. Also I don't think fluorescent paint needs a high UV input to activate (somebody correct me if I'm wrong on this please) so maybe a final output of less than 30mw would suffice.

    This may also improve the safety aspect of projecting a UV laser. I am imagining an application such as projecting onto a ceiling painted with UV reactive paint.... well out of direct eyesight.


    The more I think about this, the more my brain fizzez

    Theoretical idea:

    If one made a giant flat panel with clusters of red, green and blue dots painted in fluorescent paint (sort of like a crt screen when you look at it really closely) and then scanned a UV laser across it just like an electron beam in a crt..... could you modulate the beam to produce a picture in a similar way to a crt
    Good idea.
    Yes, you are right, really not need higher power, also UV is eyesafe light, only use white papre you can see it, , but for better effect, some UV active paint is needed.
    ok, problem is UV light is not well for man's body, if I am not wrong, long time touch the UV light will affect such as leukaemia, .
    I don't know you last theorial idea correct or not, look like it is totally different of CRT, need more correctly know the theory and talk it later.
    Best regards!
    Bridge
    Laser-wave can supply:
    Green 532nm, 4W, 10W, 15W
    blue 445nm, 2W, 3.5W, 6W, 10W
    blue 462nm, 2W
    Red 638nm, 500mW, 1W,2W, 4W, 5W, 6W, 8W, 10W
    All diodes, All optics, All mount, All laser base and housing for yourselves building lasers.
    Speical products, 532nm, OEM-V-SS, 4W, 98mm*46mm*48mm; OEM-H, 10W, 250mm*88mm*70mm
    www.laser-wave.com or www.laser-wave.net
    bridge@laser-wave.com or 463366312@qq.com
    We Chat: 463366312, Laserwave-Bridge

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    Quote Originally Posted by bridge View Post
    also UV is eyesafe light...
    Bridge, UV is NOT eyesafe. UV is known as a cause of cataracts (cloudy lenses) in the eyes. It's certain wavelengths of UVB in the suns rays that cause cataracts in many older people, that's why it's recommended that you should always wear sunglasses with a UV block to 400nm just to be on the safe side. There is also evidence to suggest that use of sunbeds without adequate eye protection can also damage the crystaline lens, as well as damaging your skin with the possible consequence of premature skin cancers.

    Look here...

    http://www.sdearthtimes.com/et0998/et0998s13.html

    and here...

    http://www.bbc.co.uk/health/conditions/cataracts1.shtml

    With regards to UV sensitive paint. You should perhaps contact 'Tocket' on this forum. I believe he was selling some UV sensitive stuff a while ago. He's a VERY knowledgeable guy when it comes to chemistry, at least he may be able to point you in the right direction.

    Cheers

    Jem
    Quote: "There is a theory which states that if ever, for any reason, anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.”... Douglas Adams 1952 - 2001

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    Quote Originally Posted by Jem View Post

    With regards to UV sensitive paint. You should perhaps contact 'Tocket' on this forum. I believe he was selling some UV sensitive stuff a while ago. He's a VERY knowledgeable guy when it comes to chemistry, at least he may be able to point you in the right direction.

    Cheers

    Jem
    I was thinking that the idea behind this product could be a start. The actual hues may need to be different

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    Quote Originally Posted by Jem View Post
    Bridge, UV is NOT eyesafe. UV is known as a cause of cataracts (cloudy lenses) in the eyes. It's certain wavelengths of UVB in the suns rays that cause cataracts in many older people, that's why it's recommended that you should always wear sunglasses with a UV block to 400nm just to be on the safe side. There is also evidence to suggest that use of sunbeds without adequate eye protection can also damage the crystaline lens, as well as damaging your skin with the possible consequence of premature skin cancers.

    Look here...

    http://www.sdearthtimes.com/et0998/et0998s13.html

    and here...

    http://www.bbc.co.uk/health/conditions/cataracts1.shtml
    So how come we have blacklights allowed? Or am I missing something?

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