Black Light and Laser?

andy_con said:

heres a little vid for ya guys

http://s80.photobucket.com/albums/j185/andy_con/lasers/uk meet 2/?action=view&current=Cap0023.flv

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That's friggin' bad ass!

Cyparagon said:

[quote author=quadcam link=1202948513/0#4 date=1202952102]
In theory though, wouldn't the florescence from the BR mix with the florescence from the blacklight thus making the dot hard to or impossible to see when they're on the same thing? If they're both florescing at the same wavelength, it's feasable...

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The blu-ray's dot will be quite a bit brighter.[/quote]

The fluorescence from the blu-ray laser probably wouldn't appear any brighter by adding a black light, though there would technically be more light reflected from that spot. Reason being is that our visual interpretation of intensity is relative rather than absolute, as are most of our senses. Basically, you eye will differentiate the "brightness" of the dot relative to the surroundings. Adding in fluorescence from a blacklight will cause the area around the laser dot to fluoresce (ideally) equally, including the area of the laser dot, essentially giving the same relative difference in intensities. And further, depending on the original lighting conditions, adding a black light, relative to a completely dark room, may make the dot look dimmer due to your eye adjusting to the increased overall brightness.

Here's a page of demonstrations that illustrate this sort of effect and show the limitations of our vision in other ways as well:
http://www.brl.ntt.co.jp/IllusionForum/basics/visual/index-e.html

thats actually really wierd i was thinking this just before i seen this topic, im gonna try that when i get my green laser (i have a blacklight in my room )

I have tested my blu-ray on a blacklight, it just look like a dim violet dot on the tube...

rkcstr said:

[quote author=Cyparagon link=1202948513/0#11 date=1203007091]
[quote author=quadcam link=1202948513/0#4 date=1202952102]
In theory though, wouldn't the florescence from the BR mix with the florescence from the blacklight thus making the dot hard to or impossible to see when they're on the same thing? If they're both florescing at the same wavelength, it's feasable...

Click to expand...

The blu-ray's dot will be quite a bit brighter.[/quote]

The fluorescence from the blu-ray laser probably wouldn't appear any brighter by adding a black light, though there would technically be more light reflected from that spot. Reason being is that our visual interpretation of intensity is relative rather than absolute, as are most of our senses. Basically, you eye will differentiate the "brightness" of the dot relative to the surroundings. Adding in fluorescence from a blacklight will cause the area around the laser dot to fluoresce (ideally) equally, including the area of the laser dot, essentially giving the same relative difference in intensities. And further, depending on the original lighting conditions, adding a black light, relative to a completely dark room, may make the dot look dimmer due to your eye adjusting to the increased overall brightness.

Here's a page of demonstrations that illustrate this sort of effect and show the limitations of our vision in other ways as well:
http://www.brl.ntt.co.jp/IllusionForum/basics/visual/index-e.html[/quote]


does this post also come in english

Deny_Defy_Hi said:

does this post also come in english  

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Heh, sorry, I suppose that was kind of technical  ;D  Kind of hard to explain it more simply, though.  I'll try to think of a good analogy.

I love my Blu-ray laser. In the dark (indoors) the beam is pretty visible. The dot reflecting off the ceiling in the room makes white and other florescent colored objects glow (not as brilliantly as a 20watt black light). I bought some glow-in the dark paint, and applied it to a white poster board. The writing last allot longer then that t-shirt video. It even makes my TV and computer monitor glow a little (when off + I don't have flat-screens).

dude, thats SICK

wouldnt it be like shining a focused flashlight in a lit room?

oh, and thats an awesome vid, wat would happen if u shone it on some glw in the dark stuff?

clwatkins10 said:

oh, and thats an awesome vid, wat would happen if u shone it on some glw in the dark stuff?

Click to expand...

Pretty much what happened in that shirt, maybe lasting a little longer.

Flourescence is where high energy photons excite atoms or mollecules to an excited state, which then drop down to a slightly lower state, then drop back down to the ground state, emmitting a photon of lower energy (longer wavelength). This process though, happens in a few nanoseconds. Say, 10ns. So as soon as you remove the laser from the material, the flourescence stops. Flourescent lights to this. the mercury metal vapour emits UV ight onto the white phosphorous coating that flouresces white. As soon as the light is turned off, the UV stops and so does the flourescence.

Phosphorescence is the same as flourescence, but the structure of the material means that the time it takes to go from that middle state to the ground state is much much longer as it is generally forbidden by quantum mechanics. Basicly, all the enery is trapped at a state slightly lower than what you put it to, and it slowly drops back down emitting light over a long period of time. Glow in the dark shirt or other materials use this to "glow".

That shirt looks like somewhere in the middle.

http://en.wikipedia.org/wiki/Phosphorescence
http://en.wikipedia.org/wiki/Flourescence

To the original question, adding a blacklight would not do much, other than cause its own effect on the material. It may look good though