white lasers

[More Power]

Thats a bit much for so little power, I think I will be focusing funds on my 12x build for now, otherwise I would probably go for it.

 

[Prototype]

Well the kit alone costs $150, so thaere's a good portion of it. Then there's the time spent aligning the beams, and the other parts. That's actually a really good deal.

 

[Tech_Junkie]

Great deal!!!

 

[Vicious]

I was doing some thinking of a white laser as well:

As "cool" and a model of today's technology it would be to have/use a white laser, I'm guessing it would be the Hardest laser pointer to create, thus probably being really unstable. You can prolly give it 5 more years until we can get some clear results. I'm also guessing it might be the laser that would "overheat" the quickest out of all laser pointer colors.

By that time, if you can get a nice, bright beam white laser that would be... Oh say... 30mw you might see this white dot and say "Oh, it's white......." What I'm trying to say is, although a white laser pointer would be a marvel in technology, and you would essentially be holding the purest form of Light in the palm of your hands, but the climax and visual effect may seem redundant to what you would want to expect.

How would you design safety goggles against a white laser anyway? Nonetheless be able to see through black lens.

 

[creanzworld17]

That would be intersting. Ive seen "white" lasers, but its just b/c of the lens.Check this out for example. It can be done - White laser pointer

 

[cmak]

Wow that looks awesome. I wouldn't mind getting my hands on that at all.

really? I thought you were allergic!

oh and you guys should really check out SightFX's White Fusion
combined with FML's Modulated Driver Extension kit, it's really a piece of work :drool:

peace & thanks
-cmak

 

[Burtle]

True white lasers already exist, they are made by a few company's now, but are very expensive. A true white laser is not one made up of a collection of other wavelengths, thats just an RGB source. True white is just that a continuum light source running from 400nm (violet) through to 800nm (dark red).

These white laser's achieve this continuum light output with bandwidth broadening fibre. The source is usually a phempto second pulsed 1064nm YAG launched into a fibre and stretched to cover around 400nm through to 2000nm. Power wise over 5W is achievable and they are very stable.

Because of this design I can never see them fitting into a hand held pointer, at the moment they are definitely a bench top device.

 

[Cyparagon]

So you're telling us tri-phosphor fluorescents like this one are not white light sources - they are ROYGBIV sources? How many wavelengths are needed to make white?

 

[FireMyLaser]

So you're telling us tri-phosphor fluorescents like this one are not white light sources - they are ROYGBIV sources? How many wavelengths are needed to make white?

To get white you need a minimum of three wavelengths, it is maybe even possible with just two, if you can them absolutely perfect. I personally don't buy the "broadband spectrum = true white"... if it looks white, then it IS true white IMO.

But the more wavelengths you add to the white mix, the better quality of the light.

 

[mfo]

So you're telling us tri-phosphor fluorescents like this one are not white light sources - they are ROYGBIV sources? How many wavelengths are needed to make white?

You answered your own question with those pics.

To get white you need a minimum of three wavelengths, it is maybe even possible with just two, if you can them absolutely perfect. I personally don't buy the "broadband spectrum = true white"... if it looks white, then it IS true white IMO.

But the more wavelengths you add to the white mix, the better quality of the light.

You can make white with just blue & yellow I believe, but as you said would be a pain to do so

 

[Things]

Yes you can make white with blue and yellow. In a laser scanner, you combine red and green to give yellow. Then you add blue to that for white. You could also use purple and green, or cyan and red

 

[Burtle]

I think every one will agree sun light is true white light as it makes up the whole of our visible spectrum and a lot more beyond, we can use that as our bench mark here.

Any thing made up from individual wavelengths to produce white is only perceived white and not true white. For true white you need a continuum light source, even a halogen light source is not true white as it has no output below around 480nm, plenty of near IR though.

Aim any RGB laser source at a optical spectrum analyser and you will see what I mean, alternatively aim it at a prism and see what colours are diffracted, you'll only get RGB, try it with the sun or a supercontinuum laser and you see the full spectrum. Thats white light.

 

[MarioMaster]

If you want to talk scientifically then yes, you need a continuum source to have true white. If you want to talk about how humans see white, then all you need to do is trigger each of the three types of cone cells in the eye equally. This can be done as previously stated with as little as two wavelengths. RGB is most common though since it can simulate the entire color gamut, although requires three lasers - one to trigger each type of cone cell.

Cone cell - Wikipedia, the free encyclopedia

 

[Burtle]

Yes, I think your agreeing with me then that perceived white and true white are very different.

My job requires me to have a coherent, collimated, polarised, continuum laser, if an RGB laser would do the job I'd be a lot better off as they are far far cheaper. I'm just trying to point out that RGB is not correctly true white, thats something very different.

With the set-up that I have I can pick any individual wavelength from my continuum source from 400nm Violet through to 2000nm IR, I can select up to 16 individual wavelengths and mix them as required, of just broaden a wavelength. It's a lovely piece of kit and anyone with interests in lasers if you ever get chance to see one in action I'd highly recommend it.

 

[Cyparagon]

a halogen light source... has no output below around 480nm

So the UV shields placed on most halogen lights are just to Fck with our heads?

 

[Burtle]

Halogen doesn't go that low, or at least any optical power un the UV is minute, we bought a batch of these so called UV blocked GU10's a while back to test this theory. I measured the spectrum of the lamp, then cut the front glass out and tried again, no difference. I then gave the glass cover to our optical coatings department to test with their OL770 very high spec OSA and they came back with the same result, it's not a UV block.

Halogen doesn't go down to the UV in any worthwhile quantity, so a UV blocked halogen is just a sales blurb that has no meaning. If you don't believe me I'll post a test spectrum done by me of a standard halogen. The kit I use is an Ocean Optics QE65000 with visible grating set-up, it doesn't lie.

I seem to have opened a right can of worms now. lol

If you need further proof and for what ever reason don't believe me here's another test of halogen:

http://www.mtholyoke.edu/~mpeterso/classes/phys301/projects2001/awgachor/awgachor.htm

As can be seen absolute minimal if any UV or anything for that matter below 480nm as I said previously.