DUMB question prob. White Laser?

[gottaluvlasers]

Hey guys and gals.

Im purely curious and admittedly not as brainiac smart as some of you. But is a White laser possible? Not through optically combining (dichros, mixed gasses combined via optics...etc...etc...). theoretically is a medium able to be lased which will yield a white beam?
I obviously know about mixing different wavelengths to *get* white. But can there be a natively lased white laser?

-Marc

[dsli_jon]

But can there be a natively lased white laser?

Ask outer-space...

Seriously, no - because 'white light', as we see-it, is 'natively' composed of much to nearly-all of the visible spectrum, ie: the Sun... (which is all the visible, and then-some... in other words, all "white light" is 'summed', from various lines in the visible-spec, some sources having more lines than others...

AFAIK, the 'closest thing' would be a 'supercontiuum fiber-laser', http://www.fianium.com/images/splash/splash-sc.jpg producing nearly the full-visible spectrum, in one head, but.. una chinga de plata, amigo!

..but you get 10 points for creativity...

ttyl, Bud...
j

[steve-o]

Supercontinuum laser ; (nonlinear fiber, very expensive) http://www.fianium.com
splash-sc.jpg

Ah- you beat me to it Jon

[dsli_jon]

..Ah- you beat me to it Jon

No worries, Cap'n... Actually, I'll go ahead and 'forecast' Marc's response:

Marc: "..Holy , that thing is friggin beautiful!! ..and, Why, exactly, are we not using these for light shows?? "

Gringo: "...well, Marc, there are a couple reasons, afaik.. #1, would be that the supercontiuum is inherently only a 'quazi-CW' laser-source, in that it's pulsed... granted *reeeealy fast*, ie: 80Mhz, but even-so, once you jam this super-beam thru a 'PCAOM' (..and they make/sell an AOTF, specifically-designed for the unique-properties of this-laser...), not sure how it would all 'work-out', for scanned-fx, etc - I'm thinkin you'd still-see dashes or at least, wierd / undesireable 'artifacts' when color-modding.. dunno, for sure, I'm just 'extrapolating'.. .. "

Marc: "..yeah, but who cares? 8W of broad-band white-light in a sexy-little box, are you kiddin' me??!!"

Gringo: "..Heh, (chuckles) yeah, I hear-ya, but also, the power-output - in the range of the spectrum we'd 'want', 440nm - 650nm-ish - this puppy only spits-out about 1.5W, out of that 8W total.. So... $uperbux, for a supercontiuum.. and I doubt the companion-AOTF is 'cheap'... all for only 1.5W, 'useable', pulsed at 80Mhz?? Mmm, it seems that our 'dream-laser' is still just that, yet... But, these are very-very cool lasers, to be sure...

..and (...I'm 'extrapolating', again.. I'd bet that in the not-too-distant future, we'll see true-CW broadband lasers, like this, pop-up, and/or come-down to 'earthly' prices... ie: if you'd told me, 4-5 years back, we'd have 90mW of fast-modulatable green in a package about the size of a tic-tac http://dl.dropbox.com/u/203420/Picop...n_cavity_1.png ..that was 'harvested' out of a $150. video-projector, I'd've said '...noooo waaayyy, maaaan!' ...Or something like that... "

Marc: "Lol"

......Or something like that...
j

[gottaluvlasers]

Holy , that thing is friggin beautiful!! ..and, Why, exactly, are we not using these for light shows??

Seriously-

thanks for the replies. Any idea what its "guts" are? solid state? 1 medium being lased?

[swamidog]

like bran muffins, the secret is magic fiber.

Holy , that thing is friggin beautiful!! ..and, Why, exactly, are we not using these for light shows??

Seriously-

thanks for the replies. Any idea what its "guts" are? solid state? 1 medium being lased?

[mixedgas]

Before there was expensive magic "holey" fiber, water cells and metal vapor cells and Hydrogen cells made a good supercontinium source. Just add a IR femtosecond or picosecond pump.

HeCad, He-Se, and AR-KR mixed lasers have had beams that appeared white since the late 60's, early 70s.

Xerox spent a fortune on compact white metal vapor lasers, with hene like beam qualities. They might have made it into the military world, but only a few made it into civillian hands. Aka the "Cook Corp" white HeCads.

Steve

[heroic]

Holy , that thing is friggin beautiful!! ..and, Why, exactly, are we not using these for light shows??

They are really, really, *really* expensive.

Also, white light optics are hard. You need to use achromats (or aspheric mirrors) for collimation.

[masterpj]

Was curious and went looking just incase: http://www.directindustry.com/prod/n...70-306988.html
found this

I wonder if these things can modulate.

[planters]

At Max Planck they managed to divide a coherent white light laser in to three separate colors, manipulate the individual waveforms and because the original beam was not simply a superposition of separate beams, but a phased broadband source (ie. a white light laser) they were then able to recombine the colors into a compressed white laser pulse with the shortest duration ever generated at 2.1fsec. Published in Science Sept 8.

[Xytrell]

they were then able to recombine the colors into a compressed white laser pulse with the shortest duration ever generated at 2.1fsec.

Wow... does that mean the physical length of the pulse would be only 630nm? Just a single wavelength long?

[mixedgas]

Was curious and went looking just incase: http://www.directindustry.com/prod/n...70-306988.html
found this

I wonder if these things can modulate.

You can externally modulate them with dicros or a PCAOM, or a galvo and a prism. They cannot self modulate, except for a limited intensity range. So now all you can do at best, with a PCAOM is pick out 8 twenty to forty nanometer wide bands. You might come up with a neat trick using a MEMs array and a few gratings, but that would be ultra expensive.

Steve

[planters]

Yes,the entire pulse is aprox 630nm in length. What still surprises me is that when I explain this, most people don't express awe. How is that?

[dsli_jon]

...most people don't express awe. How is that?

Video killed the radio star...

j