Last edited by danielbriggs; 02-19-2010 at 15:37. Reason: Added detail
- There is no such word as "can't" -
- 60% of the time it works every time -
The OP asked why the two IR wavelengths don't just cancel out. That post was my answer to that question.. In order for waves to completely cancel each other they must be of the same frequency, but 180 deg out of phase. The two IR wavelengths involved here do not fit that bill, and thus would not cancel each other out.
You're right. Phase matching is critical for most if not all NLO functions..
I thought you were asking me.. yeah... it's been a long day. I probably shouldn't even be posting. Apologies if I misunderstood you.. I don't use smileys as much as I should, so I'm sure I sounded cold or prickly when that wasn't what I intended. Happens all the time.. I really should use moar smileys
Matt-
Really nice New toy!! you probably said the power, but i am typing quick and not rereading the entire post right now. what is the power?
This, i would assume is a handheld unit? i love the yellow. How is the visibility next to a green? i am guessing bretty damn visible!?
Adam-
You seriously are a damn genius man. lol. I think my head just went boom. I really wish you lived closer. we could have some damn good beers together (and a nice cigar)The slightly longer answer is sum frequency generation, which is basically "magic", unless you've got a degree in non-linear optics. Basically you've got a pair of IR lines lasing in the cavity, and the interference between those two lines in a suitable medium creates a beam who's wavelength is related to the beat frequency produced by the mixing of the two IR lines.
i saw this when I went over to visit our english buddies! Rob probably has one of the best whites i have ever seen on a porjector. it was like looking at cotton lase. I couldnt believe it. I think the pwoer was relatively low. 50-100mW total. but Daaamn was it pretty!!!Rob (Stanwax) has a yellow/blue projector.
Makes a beautiful white.
-Marc
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Oh my,ok brain overload....lol
But this is really cool to me
So thanks for all the info!!!
DJ Matt
Arc Flash the wonderbolt
I agree completely, Marc! We'd sure have some cool neighborhood parties if you lived on my street!
With regard to the yellow pointer that Matt has... On the 2008 ILDA cruise I had the chance to sit down with Greg Makhov from LSDI for a couple hours while we were waiting for the ILDA lase-off to begin. He had one of these pointers with him and he showed it to me. Immediately I assumed that it was a DPSS green mixed with a direct injection red, but he pulled out a diffraction grating and showed that it was actually lasing pure yellow at 593.5 nm. Then he launched into a 30 minute explanation of how non-linear optical process work, and specifically how frequency-summation lasers work.
My head hurt after it was all over, but I remembered enough that when I got back home I could do my own research on the subject. And I have to say, it's absolutely fascinating what they can do with sum (and difference) frequency summation.
Tell you what: If you and Pam can make it on the ILDA cruise this year, we can all sit down with Greg and have him explain it again for us! (I'll bring the cigars!)
Clandestiny was talking about this a couple years ago... He had a krypton that was screaming on the yellow line, so he picked that line off and mixed it with some 488 from an argon to make white. He said it was a very pure white. One of these days I'd love to see that in person... (I love your description: "Like watching cotton lase!")Re: yellow + blue = white
i saw this when I went over to visit our english buddies! Rob probably has one of the best whites i have ever seen on a porjector. it was like looking at cotton lase. I couldnt believe it. I think the pwoer was relatively low. 50-100mW total. but Daaamn was it pretty!!!
Adam
Here's a graphical representation of harmonic constructive wave supersition (frequency combining).
I've just run this through a model using 10.64 and 13.42 for wavelength (just to keep the numbers sensible as its only a graphical representation)
The model does not account for standing waves or an Raman scattering effects that will definately be present in the cavity, but hopefully it will help some with the visualisation of the concept of wave combination and amplification.
Basically it is photonic music.
10.64 (ie 1064nm)
1342
Superimposed
Constructive interference when wave peaks fall in to phase
Last edited by Doc; 02-20-2010 at 07:14.
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