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Author Topic: Is it possible to make a black laser?  (Read 14970 times)

Offline shockwavemikey65

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Is it possible to make a black laser?
« on: 26/07/2009 06:21:03 »
As we can now produce almost any light color for laser beams. Why have I not seen any white lasers or black lasers or even brown lasers?? Is it even possible to produce these colors in a laser diode?



blue
green
red
purple
orange
yellow
« Last Edit: 26/07/2009 10:44:28 by chris »


 

Offline Chemistry4me

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Re: Is it possible to make a black laser?
« Reply #1 on: 26/07/2009 08:24:10 »
How on earth can you have a black laser!? ???
 

Offline graham.d

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Re: Is it possible to make a black laser?
« Reply #2 on: 26/07/2009 09:44:51 »
Specifically designed laser diodes produce light at one wavelength only; that is one colour only. The spectrum is very narrow. LEDs are similar but the construction is simpler and the spectrum is wider, but is still quite narrow and just one colour. Other colours can be created by using two or more LEDs of different wavelengths or by using a phosphor to absorb the monochromatic light and re-emit it over a different wavelength band (like in a fluorescent tube).

The lasers you are referring to are high powered (pumped) lasers and the wavelength of light produced depends on their construction and the materials used. These lasers can also produce a single colour and each laser will only work in a very narrow wavelength band. It is a prime feature of all lasers that they can only be designed for one wavelength (or colour). I would suppose you could have different coloured lasers (say R, G and B) accurately aligned to each other to give the impression of a single beam that could produce any colour by changing the relative intensity of the lasers.

What we observe as a colour is because the human eye has receptors that respond to different wavelengths. A TV only uses Red, Green and Blue but gives the impression that you can see Orange, Yellow and Violet too. This is because the receptors' bands overlap quite a lot so that light at a wavelength between Red and Green stimulates Red and Green receptors and the brain interprets this in the same way as if it were a single wavelength between Red and Green. What we see as a spectrum of colours is made up of the colours R, G and B.

As Chemistry4me implied, you can't have black as black is the absence of light. Well I suppose you could switch the light source off and, if there were no other light sources, you would have black. But you cannot have a beam which somehow negates the presence of other light sources in the way you mean.
 

Offline Bored chemist

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Re: Is it possible to make a black laser?
« Reply #3 on: 26/07/2009 10:30:47 »
Arguably, brown white and black are not colours. What wavelengths do they correspond to?
You can get a laser in any colour of the rainbow, brown black and white don't apear in the rainbow or the laser manufacturer's catalogue.
Technically, with a sufficiently short pulse, you could get something that aproximates to white light .
« Last Edit: 26/07/2009 10:33:04 by Bored chemist »
 

Offline RD

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Is it possible to make a black laser?
« Reply #4 on: 26/07/2009 11:45:19 »
Ultraviolet light (invisible to humans) is sometimes referred to as "black light".
Ultraviolet lasers exist.
 

Offline lightarrow

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Is it possible to make a black laser?
« Reply #5 on: 26/07/2009 12:09:13 »
As we can now produce almost any light color for laser beams. Why have I not seen any white lasers or black lasers or even brown lasers?? Is it even possible to produce these colors in a laser diode?
About the black laser, you could replace the "photons" with the "darkons"  ;D

Of course it's impossible, black is the absence of light (the fact UV or others radiations are non-visible, don't make them a "black beam").
 

Offline wanhafizi

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Is it possible to make a black laser?
« Reply #6 on: 30/07/2009 05:47:54 »
As we can now produce almost any light color for laser beams. Why have I not seen any white lasers or black lasers or even brown lasers?? Is it even possible to produce these colors in a laser diode?

Guys, about black lasers or "darkons",  :D...

Is it possible to create a laser that will produce a destructive interference wave pattern, so that it will dim out another laser?
 

Offline Don_1

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Is it possible to make a black laser?
« Reply #7 on: 30/07/2009 08:24:58 »
I have already produced a black laser.

Trouble is, when I took it to the patent office, no bugger could see it, so they told me to take my black light and shove it where the sun don't shine!

I did, now I can't bloody see it myself!
 

Offline Chemistry4me

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Is it possible to make a black laser?
« Reply #8 on: 30/07/2009 08:37:45 »
So that's your dark secret! I should have seen it coming!
 

Offline Don_1

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Is it possible to make a black laser?
« Reply #9 on: 30/07/2009 08:42:39 »
And I should have seen that coming, but with all this black light around, I can't see a bleeding thing!
 

Offline lightarrow

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Is it possible to make a black laser?
« Reply #10 on: 30/07/2009 14:52:43 »

Guys, about black lasers or "darkons",  :D...

Is it possible to create a laser that will produce a destructive interference wave pattern, so that it will dim out another laser?
It will dim it in some regions of space but it will brighten it in other regions; energy remain conserved.
 

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Is it possible to make a black laser?
« Reply #10 on: 30/07/2009 14:52:43 »

 

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