RGB Dye Laser? How Dye Lasers Work: Viewer Questions
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- Опубліковано 28 вер 2024
- Episode 36
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Viewer questions!
Some people had questions on Dye Lasers:
Is it possible to mix Dyes in the same cuvette?
www.jonsinger....
How is it that focusing a Nitrogen laser into a Line evern sets up lasing in the first place?
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#NitrogenLaser
#DyeLaser
#optics
that is really beautiful to see the beams emerging as different colors out the cuvette
Man I love this channel. I know YT keeps recommending your old videos but every one I watch is amazing. Your designs are elegant and your explanations are really clear, doesn’t resort to hand waving either. Just spot on!
I’ve never seen so many folks worked up and excited about tinkering with DIY “at home” lasers.
Even a local buddy of mine, (who like myself works on test equipment and stuff for a living)…
Despite my many attempts over the past few years…He’s never been interested in lasers at all. But after watching a few of your videos he started building several small lasers like yours.
The bug finally bit him.
It’s awesome and I really look forward to your future projects and watching your channel grow
Awesome, I am glad people are following this stuff! There is other cool stuff in the pipeline ;-)
كل التحية والاحترام
This is the best video i could hope to find explaining dye laser to a newbie only familiar with DPSS and direct diode lasers.
Much appreciated!
I hope you’re doing well and always excited to see more content from you.
I am thanks, I hope you are too? Yeah, it has been a slow month, work is crazy and life is crazy, but: I now have a lathe, three projects are complete, more or less, just waiting on sundries like project boxes and the like. I need to plan better!
Vers interesting video! Thanks for showing us!
NICE!!!! My first thought was to somewhat accuratly draw the emissiom and absorbtion graphs and use the superposition principal to compare the results of various intensities, then perhaps use variable 'concentrations of each dye to get desired results. Can you mix dyes in one cuvette?
Hi Les! I've been able to make a TERP-N2 Laser based on your TEA - Design. Thank you so much for putting the info out there! Short question: How much transmission does your usual dye-Outcoupling mirror have? Also, I think I'll try to mix dyes into epoxy/PMMA and make a Solid-State-Dye laser. That would be pretty cool :-)
Cool! I am glad you found the design useful! The OC is 50:50, however I have tried 30R:70T and it works just fine as well. I actually have a PMMA Dye laser in my box of "yet to be demo'd stuff" ;-) It will be challenging, but there is no reason why it can not be made to work.
nice..
...looking forward to the ruby : )
Cheers! I have ordered a suitable flash lamp off of ali-express, it will make an appearance eventually!
I am curious, with the combined dyes the "repetition rates" that changed how the two competed were, if I heard you correctly, in the 20-40 hz range. Would circulating the dye affect that?
Circulating the dye may well solve it, though at this stage I am not sure what the mechanism is. My first thought was perhaps triplet absorption. There is a lot of work to be done here for sure!
Aha , very good and intuitive explanation. Now I understand how those tinfoil lasers work.
Amazing work Les! this is a really nice demonstration how this works i like it ;-) also looking forward to seeing what you come up with for the ruby laser rod i presume your going to come up with some sort of Zenon flash-tube setup? or you may already have!, the powersupply for that i will be interested in ;-)
Thanks! Yeah, this one will be done at some point. I suspect the threshold is pretty low, so I am hoping to make something compact. Xenon flash is the way to go, but I also heard they can be diode pumped as well ...
@@LesLaboratory Hi! Yes, I've actually made a DPSS Ruby laser and got a video on my channel regarding it. I would be honored if you'd take a look at it. The ruby rod however must be very short (about 5-8mm), otherwise the threshold is very high. I got it to work with 300mW 405nm pumplight and a set of specialised mirrors.
@@WoodenWeaponry Beautiful work!
I'm trying to get into lasers and would like to build a dpss laser... Where would u suggest I look for more research and affordable parts?
Will it lase in the axis of the collimated pumping beam?
Hey Les - in a cuvette dye laser without external mirrors, do you notice that lasing only happens on 2 faces of the cuvette? I've seen this in my cuvettes. I thought it was due to how the cuvette is made, and internal reflections amplifying the emission.
If you hit it super hard (>100kW) it will lase on any faces regardless of internal reflections, but in a proper dye laser setup, then yes, you will find that only two faces have good output. I think it is more likely due to how the four pieces of quartz are assembled and fused. I suspect distortions at the fused boundary spoil lasing along 2 faces.
@@LesLaboratory Makes sense - I thought it was the boundaries as well. Thanks!
Just had a thought: Could tonic water be used as a dye laser?
so if this gain happens without a resonator then why does the same not happen in say a ruby laser or gas etc?
Hi Les, really inspired by your videos. I've been studying your DIY white laser and been trying to duplicate your dye laser setup. Could I ask what is the partially reflective mirror component that you used? (If it's purchasable by Thorlabs, Edmund Optics). Is it just a regular 99% broadband VIS coating with some transmission at 1%?
Also, I am thinking of using a ND:YAG (@ the 3rd harmonic 355nm) to excite the dyes so I can play with the pulse width, pulse power, etc. Love to sync with you if you are interested.
These lasers dont require much feedback, so I used 1 inch plate beamsplitters from thorlabs, and they work just fine: www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=914
50:50 or 70:30, both work well.
Interesting your should mention this. I have a 355nm YAG as well that I repaired some time ago. I just need to devise a circulation mechanism for the Dye, but haven't quite gotten round to it yet!
Sure, drop me an e-mail!
@@LesLaboratory Thanks Les! Sorry for my late reply. I have some thoughts on the circulation (assuming you mean moving the liquid dye in the cuvette around). I'll ping you offline or we can have a chat here (for any intrepid readers), up to your preference!
I am looking to buy Coumarin 460 for my mixing. Molar mixing seems to be sort of straight forward if i know the Molar... but love to hear how your DIY dye mixing process went for you.
Also saw you dropped a new video on the ND:YAG laser, I'll check it out soon.
Cool. Liked the explanation of the competing dyes. There was an article in the mid 80s in the magazine, 'Scientific American,' I think, that discussed some of these possibilities. But not to the extent of what this presenter did. My thanks. Quantum effects are interesting. Fluorescence, for instance, will often happen when the material is at a room temperature, and not when it's hot. Uranium glass is one such material. Getting back to the SA article... I had the notion that the US military had been funding the research that lead up to that article.
Thanks! Oh man, I loved the old Si-Am magzines. I used to skip school and go read them in the library! Yes, there are some pretty cool and interesting things to find, some of which seem almost forgotten. It would be interesting to repeat seom of the old experiments with modern equipment.
@@LesLaboratory Me too.
How does the dye get its population inversion? The photons for population inversion in the dye is also supplied by the nitrogen laser? Thanks.
Yes, the population inversion is caused by the optical pump energy from the nitrogen Laser. This is analogous to optically pumping Ruby for example, with a flashlamp.
Great video!
Would it be possible to pre pump the die with a UV LED to enhance the output power and/or increase the depth of the lasing Chanel inside the die?
Anfortunately, no. Doing this would force the dye molecules into their "triplet state" where laser emission cannot occur. Also the output power from a UV LED pales in comparison to the output of a nitrogen laser (10's to 100's of kilowatts peak)
That's cool... I was asking myself these questions yesterday, and today the answers pop up in my UA-cam suggestions... do you think Google might have bugged my mind?! (puts the X-Files theme tune on)
Probably! It's creepy right? 😕
If I put an AOM in between the HR and the dye cell, do I sync to the pump laser, slightly off or at some multiple of the pulse rate to qswitch it? Thinking the stimulation saturates faster than I can switch it and since the lasing is superluminal does a qswitch idea for building up a pulse even make sense? Looking at ways to up the game for the super continuum laser pump.
No the dye has a very fast decay time in nanoseconds or less and a long regeneration time. It needs a fast pump source or to have the dye moving quickly to lase.
With so many wave lengths in play how do you protect your eyes from the LASER radiation or is the power level low enough
that reflections do not to pose a eye hazard ?
To shield against UV is easy, regular polycarbonate safety glasses will do. For Dye lasers, well they are problematic. Laser goggles for these wavelengths show up rarely and so for now I am using good planning, and cameras for setting up.
what about glow sticks? can we take the chemiluminescent liquid and put it in a cuvette inside a fabry perot cavity and have it lase itslef?
Unfortunately not. Triplet state absorbtion is a problem, which would quench Lasing (if the dyes in those will even Lase in the first place). To get a continuous wave Dye Laser, the Dye has to be circulated past the pump beam at very high velocities to stop this from occurring.
@@LesLaboratory hmm all this stuff confuses me, i figured since the chemicals are creating spontaneous emissions then we could create stimulated emission much more by using mirrors no?,, suppose we have an imaginary pin point light source sending spontaneously emitted light in all directions and we add this inside a fabry perot would we not get a collection of light rays all bouncing back n fourth directionally between the mirrors even though there is no stimulated emission we should still get a beam output no?
Can an electromagnetic field be used to align the photons to encourage lasing?
Great Les. It's possible to pump the dye cuvette with a 5w 445nm diode laser focused and get it to lase?
If you calculate the power it takes, you'll find that it's a lot higher than 5W for that much volume of dye. It is, though, possible to pump a 'jet' CW dye laser with a diode laser. I once ran Rhodamine 6G CW, using a 300 milliwatt green DPSSL module as the pump source.
@@DerangedTechnologist thanks
it is also possible (according to the literature) to pump a dye cell in pulsed mode with high power 405nm as well, though the optical setup if I recall was quite complex, and involved driving 405nm Nichia diodes in a pulsed regime (several 10's of amps at around 100n sec or so)
@@LesLaboratory I saw a report, some years back, that if you keep the pulsewidth below about 350 nsec (IIRC), you can run a diode laser at 3X its rated maximum current, so this seems quite possible, though I'm not at all surprised that the optics were complex.
Also I stumbled upon a paper that says that some german researchers did this: they took an fluorescent acrilic plate (disk shaped) and rotated it fast (don't remember rpm's) , side pumped with a continuous wave laser diode.If the rotation is high enough, the spot hit by the pumping source is hit only for a tiny amount of time and alows it to lase.I almoust build the setup , not finished yet because I burned the 405 diode 🤫 in testing the drive.Replaced the disc on a hard drive with an yellow green acrilic disc.
RYB
can i not take a strong enough black light emission pass it through a lens unto a cuvette like this and make a laser beam?
It the black-light was very high power and very short duration then certainly. But you would be talking kilowatts and nanoseconds. Nitrogen Laser just happen to be a relatively straightforward way to achieve this.
@@LesLaboratory i thought your n2 laser was cw not pulsed? see this high power or peak and short duration having to do with the short life time of the gain mediums exited state etc etc to make it work is something i never understood and i was also told ruby lasers can never function cw because of this yet now we have cw ruby lasers!!! , why do we even need high power?we can already see this liquid fluorescing under the slightest black light condition so why is this light simply not amplified between mirrors to get our beam despite it being a weak beam?
10th of a mill you say? but the beams appear to be at least 1/2 to 1 mill?
this is outstanding. very interesting, I didn't know it was possible to see so "hands on".
Thanks!
Wow such a nice experiment😎 would love to see the ruby Laser i bought the same rod on ebay and i plan to build my own.
Yeah, it was too good to miss. I expect the threshold will be fairly low, and should be a neat build.
same here : )
..got a qswitch and 260j input ( 140 threshold translated ), prism,
...got possible oc from silicon sam
..getting close
I wish i could test a theory on laser crystals with the use of a scintillator crystal more in particular the GAGG crystal and make a true yellow laser or white laser in the same was white led torches are made
I'm learning so much about lasers from your video's, very exciting stuff!
Thanks!
Could you combine different dyes around a rotating cylinder, so you get an alterating wavelenght laser. If the cylinder rotates fast enough, it would Look like a white laser.
There was a paper, (I forget the title) where they pumped 3 microcuvettes, mounted staggered which gave a more or less RGB output. Lately I have been building Supercontinuum Lasers for a true White-Light Output: ua-cam.com/video/w1wSHizmbYg/v-deo.html
Could you combine different dyes around a rotating cylinder, so you get an alterating wavelenght laser. If the cylinder rotates fast enough, it would Look like a white laser.
There was a paper, (I forget the title) where they pumped 3 microcuvettes, mounted staggered which gave a more or less RGB output. Lately I have been building Supercontinuum Lasers for a true White-Light Output: ua-cam.com/video/w1wSHizmbYg/v-deo.html
I like this.
I has absurdly big capacitors for no reason.
Thanks! Oh, I have... ...reasons!
so what if you got photons traveling along the axis of this line in a cuvette, you got the same happening in a hene laser yet it needs mirrors to create stimulated emission output so why does the dye cuvette not need mirrors?
The single pass gain in a Helium Neon laser is about 1% or so, which is pretty low. The gain (or amplification) of Laser dyes is very high, so high that amplification of the light can take place in less than 1mm.
@@LesLaboratory i suppose it has to do with atom density in a liquid being much higher than in a gas is that part of it?
Excellent, Les! (Thanks for the mention and the link!)
Thanks Jon!
ty for the videos, can u refer a reference, about dye lasers ?
i am looking to find a dye mediium which has absorption range near inferared, or in it, how can i find suc material ?
There are IR dyes for dye lasers, however, such a dye wodul also lase in the IR, as fluoprescence almost always results in longer wavelength than the pump in all but a few very special cases.
@@LesLaboratory Thank you so much, can you name a few references so i can read more, i am really new in this field and my degrees are not in optics or physics.
i mean both generally reading abot lasers and more specifically about dye lasers (and the ir dyes)
4:40 the Green spot (the brightest and largest one) is from the composite of Coumarin and Rhodamine? Could it change color through changing the concentration or ratio of Coumarin and Rhodamine?
Maybe, but both dyes compete heavily for gain, and so it is very sensitive to dye concentrations. There are a few funky dyes I have been looking at recently, but they are out of my budget at the moment!
@@LesLaboratory I wonder where the green luminescence came from, maybe it came from the new energy gap (then the composite seems like a new molecule) between double levels form Coumarin and Rhodamine B? if this is true, then its color (wavelength or energy gap) will not change when the concentration or ratio of Coumarin and Rhodamine changes.
Fluorescence Resonance Energy Transfer (FRET), maybe.
thanks a lot!
You're welcome!
Nitrogen laser with 250μJ peak pulse energy, I bought a Nitrogen laser with 100μJ peak pulse energy, can it excite dye laser?
Shouldn't the lasing be directional? I get that pumping will induce fluorescent which in going to be all directions. But side pumping a line I still would not expect lasing in the perpendicular direction of the pump. Do the fresnel reflections from the two orothogonal faces of the cuvette give it enough cavity action in the direction of the line focus to get above lasing threshold?