# Anybody heard of a 555nm laser?



## drpepper1024 (Feb 13, 2005)

Just curious if anyone had ever seen or heard of a 555nm laser, which im sure most of you already know, would appear the brightest for the least mW because of the human eye's extreme sensitivity to that wavelength. Talk about a visible 
beam! I think I would probably sell my soul /ubbthreads/images/graemlins/evilgrin07.gif, if I thought i could get one, especially in a pointer style.


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## Spec (Feb 13, 2005)

CNI states they can make one, however, I have never heard of any compound or ionized gas that can do it.

The closest I know of is xenon ion 559.227nM and thats a very weak transmission line for xenon.

Portable is right out of the question /ubbthreads/images/graemlins/wink.gif


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## enLIGHTenment (Feb 13, 2005)

555nM can be done with a dye laser....or a FEL, for anyone who happens to have a spare particle accelerator lying around.

Portability? Not exactly.


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## Bond007 (Feb 13, 2005)

Well there won't be one available in pointer style,

Like Spec said though, CNI have told me that they can make one. They already make 556nm modules from 10 to 50mw. 50mw at 556nm must be phenomenally bright /ubbthreads/images/graemlins/ooo.gif


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## Shiftlock (Feb 14, 2005)

I have an uncle who runs a biology lab at UPenn. They have a 25mW DPSS 561nm laser, which they recently purchased to replace their 568nm Argon. So there are some odd-ball DPSS wavelengths possible.


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## comozo (Feb 14, 2005)

On the bell curve distribution 
532nm=.885
555nm=1
593.5nm=something close to .885 (yellow pointers)
All things being equal you would see about 25% increased apparent brightnest.
Sams Laser FAQ has the facts.
Like the line in the movie Field of Dreams "build it and they will come", in this case build it and they will buy.
I'd like one too.


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## Canuke (Mar 1, 2005)

comozo made my first point; the difference between sensitivity to 532 and 555nm is negligible.

The second point is that 555nm is the photopic optimal response; that's because for photopic vision, red and green are more sensitive than blue. But for your average 5mW laser, you should want one that approaches the optimal point for night (scotopic) vision, as you're likley to be using it in the dark.

Scotopic vision is only senstitive to blue and green, with red not registering at all. Therefore, the scotopic optimum point is around 500nm, just a touch on the blue side of traffic light green.

This would mean that the best color for seeing the beam of a 5mW laser, is cyan... which, oddly, is the color of the laser scopes used by Overwatch snipers in Half Life 2. That's the exact opposite of what a sniper ought to use; they don't want the beam giving away their position.

(edited to put the right words in their places) /ubbthreads/images/graemlins/icon15.gif


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## bg2vo (Mar 2, 2005)

Hi Canuke, for these two phrases:
'555nm is the scotopic optimal response;'
'for night (photopic) vision'
should they be like these?
'555nm is the photopic optimal response;'
'for night (scotopic) vision'?


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## Canuke (Mar 15, 2005)

dictionary.com says yep, you're right bg2vo.


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## Raccoon (Mar 15, 2005)

Whichever is correct, I want a cyan 555 laser! /ubbthreads/images/graemlins/frown.gif

They're showing up in all sorts of video games now, including Tekken 5.


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## comozo (Mar 15, 2005)

I posted a question on another forum. Short version is two lasers with an output of 5mw at 507-508nm and 555nm the laser producing 555nm light would appear brighter. So the eyes response would be photopic.


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## The_LED_Museum (Mar 15, 2005)

[ QUOTE ]
*Raccoon said:*
Whichever is correct, I want a cyan 555 laser! /ubbthreads/images/graemlins/frown.gif 

[/ QUOTE ]
555nm would not appear cyan, it would appear as a very, _very_, *very* slightly yellowish green.
Cyan would generally be considered wavelengths ranging from 485nm to 500nm.
Just FYI. /ubbthreads/images/graemlins/smile.gif


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## comozo (Mar 15, 2005)

The color name for that wavelength would be Chartreuse. Even the so called green laser we use are Chartreuse. I don't have a green laser pointer I have a Chartreuse laser pointer


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## Bond007 (Mar 15, 2005)

Lol,

How did you find out the official name for 532nm then? I'd like to see a good concise colour/wavelength chart as such. /ubbthreads/images/graemlins/smile.gif


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## comozo (Mar 15, 2005)

I just look at my box of Crayola Crayons and I see green and I see yellow, my green laser is neither, but is both. Seriously, the color Chartreuse is defined as green mixed with yellow. Awhile back someone did post a concise wavelength vs. color spectrum, but I have not been able to find it. So by the power invested in me or not I declare hencefore that all green laser pointers shall be known as Chartreuse laser pointers.


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