Wow, this must be one of the most interesting videos I've seen in a long time. I'd heard of these but like you considered them to be very difficult and expensive to make. Absolutely fantastic job! What struck me most were the spectral variations, especially how far they extended into the red. I guess these are related to pulse energy variations, which demonstrates exactly how non-linear the process is.

I had no idea any of this was possible! Really really interesting stuff! Why is the dye laser necessary rather than use n2 direct? If it's only to produce a wavelength compatible with plain glass fiber, what do you think of trying quartz fiber? Maybe it's not available in single mode?

Wow! Absolutely fantastic! I've only ever seen manufacturers scant few promotional images. To see it _in person!_ You must be pretty jazzed!

As a dropout optics/laser engineer, I love seeing things like this pop up in my feed. As a fan of Ben at Applied Science and, er, whomever runs Breaking Taps, it's also a delight seeing them in the comments here. (I've just realized I have no idea what his name is.)

OK, first, the name "supercontinuum laser" is a huge missed opportunity in our retro sci-fi. Second, I have no idea how I've circled the sun more than 40 times, admiring lasers for a lot of that time, and have never heard of this. Simply amazing. As an audiovisual engineer, I can't help but wonder if anyone's doing research on the optics to bring this to video projection. A projector with this kind of light source would blow any OLED TV out of the water, particularly with an ambient light-rejecting screen. Great stuff, Les. 👍

Absolutely incredible. I did my master's research on self-phase modulation and suspected for a long time that supercontinuum could be generated using self-phase modulation on a budget. Keep up the good work.

Wow, highest level . Speckle is everything with perfect phase and holographic visual effect.

If i could, i would give 5 thumbs up for this! Amazing experiment!

If you pass the output of the prism through an LCD screen with the backlight removed then through another prism to recombine the spectrum you can dial up any spectral profile of light that you want as the LCD can display spectral line masks.

Les, you have absolutely outdone yourself! This is incredible and I have always wanted a supercontinuum laser. I hope to make one also one day.

It was only a few days ago that I first heard about supercontinuum lasers, and there's Les' Labs new video discussing the topic! Excellent!

This is the coolest laser video I have ever seen. I love lasers

Fantastic. I'm particularly impressed with the retrieval of a '75 paper (kudos to the authors for the abstract writing!), to solve a "mundane" 2022's home lab problem.

Hehe, awesome use of standard fiber! As fiber is not single mode for VIS, I would expect higher modes traveling longer path in the fiber, and experiencing higher super-continuum generation.

Welding mask lens with a high enough shade level that I don't know offhand? Awesome as always! Man, you deserve way more subscribers.

Please bring some of this stuff to the UKLEM in March!

Nifty AF !

Absolutely awesome!

Absolutely spectacular Les!

Sooo cool. Amazing work!

It's very interesting that it doesn't actually require a PCF! I wonder if this could be pumped by a MOPA 532nm source(1064nm MOPA pulsed fiber laser and a homemade doubler). Affordable commercial units can go down as low as 1-2ns pulse length and have peak powers of around 16-20kW. Definitely going to have to try replicating this!

Absolutely brilliant.

At first, I'm like "it's impossible to convert monochromatic into multiple wavelengths". Then I'm like "okay, perhaps they can be stretched without requiring half the entire distance of the universe". So, as long as there's less or equal to the amount of energy from the original, it should be possible. Probably not that efficient, but really "cool" 😀

Amazing work! This is really cool, super impressive you were able to generate that right on your bench! I was reading about supercontinuum a while back in regards to optical coherence tomography, but ruled it out as a project pretty quickly due to the same financial reasons. 💸 So if I'm reading the paper correctly, this effect is generated because of the pulse duration causing self-phase modulation in the fiber, and the wavelength causing stimulated raman emission. The pump laser stimulates a bit of raman emission at a higher wavelength, and those photons go on to cause more raman scattering, etc etc leading to a series of discrete, longer wavelengths propagating in the fiber. Meanwhile, the pulse duration itself is causing self phase modulation stuff, which broadens the wavelength too. And since it's in a fiber, more length == more broadening of the continuum. Is that roughly how it works? Really cool stuff! Thanks for sharing this!

Amazing work, just found your channel and started digging through. Keep up the excellent work!

Fan FREAKING tastic Les!!! I love supercontinuims, but never thought it was achievable without a femtosecond laser. I’m so impressed by this video. Thank you for sharing!

Pretty cool!

This is amazing

very cool. well done

Amazing.. Nice job!

Laser Les is the Best!

Awesome... thank you for digging through the research and sharing

What can I say ! more please ! Outstanding work, a truly incredible sight to see....cheers.

Very impressive!

Left you a comment yesterday but it looks like it's been deleted or they're still a bug with youtube. So I'll paste it here again As soon as I saw the laser video posted by rocketMan340..... I sent you a comment about 5 minutes after he originally posted it Looks like maybe he's been watching your channel 😁 which is awesome! I was always stunned at his content over the years ....more than a decade I've followed him I think. Such a shame that he doesn't do any real commentary or anything just short videos. Would be insane to hear him discuss and explain his lab and equipment. Mind-blowing stuff really. He said some of the most insane rare stuff I've ever seen

Wow, what an amazing project! Great idea to go back to the original paper to see how they did it, huge kudos all around!

Holy mackerel congratulations on this!

Wow! I didn't even know these things existed (supercontinuum lasers) until I saw this video! Thanks for sharing.

Mind = blown So cool !!

That is awesome, Les! Gonna have to buy some telecom cable now 😄

Mind blown! If you'd posted this on April 1 I would've been convinced you were having a laugh.. I've been interested in/experimenting with lasers for some 30 years and never imagined this could even be possible, let alone on a home lab budget! I've had a selection of fluorescent dyes on hand for years now, but this has convinced me to take the next step and order a quartz cuvette to delve into dye lasers. Did you have much luck with any other laser dyes?

Thanks!

So many argon and diode lasers, but alas, no nitrogen one. Amazing results, what made it to video is cool enough, I can only imagine what it's like in person. Had the privilege of playing with some old Omnichrome white light lasers back in the early 2000s and those were unworldly.

Very interesting project. While Nonlinear optical phenomena are interesting, they usually require extensive and expensive optical setups. It's great to see someone doing Nonlinear optics at the comfort of their own homes. Keep it up👍👍

Absolutely beyond fantastic and SUPERcool. I've of course been aware of this form of light for many years now, but have never seen anyone actually show exactly how its produced. I strongly suspect supercontinuum radiation will, in the very long term, ultimately supersede LEDs and diode laser/phosphor combos as sources for general illumination. But it's gonna be a loooong time. One of my favorite science experimentation channels by far.

Wow! Can you share more details about your experimentation with various fiber lengths and types?

Bravo. I'm headed to the Silacon Valley junk yards. Next week. I'm sure I can get a spool of fiber, I've got a N2, like yours, a super cw/pluse Dye Laser system. I wonder if I can use some C130, I have a little C120, maybe some RB, too. Laser diodes I have 450 NM, cw, a couple of watts., 1 at 440 NM. 2 watts, pluse ot cw. Exciting to study, maybe a cavity dumper polarizing plate, some 1/2 and 1/4 wave plates across the dyecell. Thanks, Les...! Cheers

Awesome! I wonder if there is any visible effect when you apply stress or strong magnetic fields to the fibre. Might there be scope to optimise by controlling the temperature of the fibre?

Very interesting topic Leslie....Sorry for the very stupid question, but all the magic of supercontinuum generation happens inside the fiber waveguide ? I may have missed the explanation here, but I'd sure like to see a separate video on the subject.

You see a donout mode from the output fiber facet because your output is multimode. BTW: try using a solid state laser for generating Supercontinuum like an Nd:YAG. Has sufficient peak power to drive a supercontinuum process.

This actually blew my mind! Amazing job, however I'm left to wonder why the output so perfectly centered around visible light, like it is the exact same wavelengths we are able to see with our own eyes... does it have to do with the equipment used to measure the spectra (ie. limited sensitivity in the Ir range) or is something related to the bandgaps of ther atomis in the fiber (like how we don't have x-ray emitting diodes or microwave emitting diodes because of the electronic band structure ...)

You're most likely getting the Donut mode because of the fiber you're using. For 400nm this is a low order multimode fiber and you're not filling it with a single mode laser in the first place. The first order mode also converts into the supercontinuum much faster and therefore experiences higher losses before the end of the fiber is reached. The continuum generated from that simply gets lost along the way. The second order propagates much further before being converted, so what you're getting out at the end is what's left of the supercontinuum from the second order. If you shorten the fiber you may be able to get the light from the first order conversion, but the second order is probably still Blue at that point. Self-phase-modulation, is a pretty common problem for fiber lasers. I would be curious how stable this is from shot to shot. The Thorlabs kit is definitely a different beast and hard to compare to this.

Great work. Can you also make a video demonstrating how RGB lasers achieve white and other colors?

Very impressive! I remember some time ago you mention your home-made nitrogen lasers had quite good modeprofile, so it maybe interesting to try to couple them directly into the fibers and see if that works. As for the donut: Telecom fiber is designed to be single mode for 1550 nm, if you have shorter wavelengths, you can obviously still get some higher order modes in it. For example the Thorlabs 1550BHP Fiber (single mode, non-PM, 9 um core) has a cut off wavelength of 1260 nm, i.e. and wavelength shorter than that and it may transmit some higher order mode. Edit: Upon thinking about it, that maybe the coherent superposition of the two TEM01 mode for the two polarizations you're seeing as a donut. Maybe if you hold a polarizer in the output you see a clearer shape.

Thanks Les! I'll just agree with all of the others' comments.... Wow! amazing, fascinating, mind-blowing,.... show me more! Happy New Year to everyone! 😎

This will be a great piece of kit for analytic chemistry or spectroscopic research. My background is in optical fibre sensing and photonics, and am wondering about two two things: Firstly, the effect of path length on output spectrum, have you performed cut-back tests? and secondly, have you been able to test the effect of straining of the optical fibre? I would appreciate to hear about how these effects may or may not affect the output spectrum. Thanks for all your videos and I wish you well. 😀

You mentioned stilbene-3 (a.k.a. stilbene-420) is a bit difficult to obtain. Would it be worth trying a related dye, 4,4′-Diamino-2,2′-stilbenedisulfonic acid ? If you still have your optical bench setup for fiber supercontinuum, a quick, fun, test would be to try a cuvette of clear liquid laundry detergent. Laundry brighteners often use 4,4′-Diamino-2,2′-stilbenedisulfonic acid. It is probably too diluted to have enough output, but who knows? Sometimes even "Jello" (tm) can be made to lase. Thank you for the best DIY science on the net!

I still have no idea how that setup made Supercontinuum Laser and why, but sounds like Start Trek staff.. very cool.

Wow

Wow! Super cool! It's interesting that when you remove the attenuator that it seems like the colors have to "warm up". Is that an artifact of the camera or does it really take a moment to produce the whole spectrum? and is that flickering of the final result visible IRL or is that an interference of the camera shutter rate and 100hz laser pulse?

Have you ever thought of playing with organic dyes? I don't mean rhodamine so much as new ones (to me at least) like anthocyanin, curcumene, even chlorophyll. Anethole looked interesting for its refractive index.

Fantastic video!. I wonder how far one could push this with a 532 nm, nanosecond long pulsed laser with nice beam quality in terms of efficiency and spectrum generation. With current laser technology (the original paper is old!) could one get a better deal (also thinking in terms of the nice 1064nm lasers)

What exactly is generating this multi-line coherent light?? All I see is a 420nm range laser coupled into 200m of single mode fiber. I’m a bit baffled. This is really outstanding.

Hi Les, I am really enjoying your videos. I have an old spectra physics 337 nm Laser (up to 30hz or 60hz in pulse mode) that I'm going to use to try this. I just ordered 30M of 50 micron telecon fiber. Would I get some sort of SC effect using a direct coupling into the fiber or do I need to use a longer wavelength setup with Dye? Also what do you use for your attenuators?

One day we will have true white laser lightbulbs in local market :D

What do you get if you try to use one of these in a Michelson interferometer?

So should the takeaway here be the following?: 1) Find a source emitting in a frequency higher than all others you want to include in your contiuum/spectrum (or wavelength shorter than all the others you want to emit) 2) Find the longest fiber-optic cable you are willing to buy (I believe "you get what you pay for" will translate directly here) as,: 3) Dispersion through the length of fiber will handle the rest. It's a kneejerk guess, but the dark spot you are observing on your screen could be some kind of incoherent spot of Arago. A spot of Argo is a characteristic feature of how a central obscuration will cause light to diffract around the edges. This spot will form at a distance behind the obscuration due to the wave nature of light interfering with itself (coherently, for this explanation) at a distance behind the obscuration dependant upon the wavelength of light and diameter of the obscuration. The input beam to the fiber looked pretty Gaussian to me overall, but it was certainly far from perfect as pointed out. (I'm not familiar with dye lasers, but I assume that this is a feature of the state(s) of the gain medium and resonant cavity used for amplification.) I think that this imperfect beam is propagating, and dispersing (quite messily, due to the deviation from a perfect Gaussian input profile) and could like you said: be dependant on core diameter of the fiber, which is intended for telecom, was probably for wavelengths of 1300 nm - 1650 nm. This combination of dispersion-inducing fiber coupled with an imperfect irradiance profile at the face of the fiber leads me to think the following: The 90 % of energy doesn't just disappear if it does not couple within the NA of the fiber. It likely continues to propagate within the cladding of the fiber as well. SO! My guess is you actually are coupling most of the source power into the fiber. It's just primarily propagating in the cladding. NOT the core of the fiber. This method of propagation would almost certainly give rise to the spot of Arago you are probably observing. The core of the fiber is acting as the central obscuration. This is however just my educated guess. I'm sure dye gain mediums are not cheap if they're anything like dyes used for fluorescence spectroscopy. That being said, I'd still like to see the cheapest BOM (bill of materials) that one could muster to reasonably pull this off (parts from ebay, etc.). Also: I suppose you could try using an axicon to bring that ring down to focus at a point. What you choose to do with this... well, use your imagination I guess. Sweet vids. Keep 'em coming.

the donut mode was probably because the short wavelength of the supercontinum is in the multi-mode regime of this single mode fiber

Nice! If you could see the bare fiber, you would probably see a lot of light leaking out too. Not sure why the red end of the spectrum is so unstable 🤔 By the way the single mode fiber should be TEM00, gaussian. I suspect that your supercontinuum leaks into the cladding and produces the donut shape

Now get your hands on a Polychromatic Acoustic Modulator and cycle through the colors :-). Those used to work with Mixgas argon/krypton show lasers

Could this be used in creating full color holograms with just one laser? I believe they currently involve the use of a red, green, and blue laser separately.

Thanks for the video Les, really fantastic. I'm trying to replicate this on even more of a budget than you, so I've been looking at DIYing a TEA or low-pressure N2 laser. However, I saw your comment that you only get full visible at 32 Hz pump, and from what (admittedly little) I've read, these simple air lasers only pulse around 2 Hz. I suspect this is a characteristic of capacitor design. Do you have any suggestions for improving the pulse rate of a TEA?

Hey Les, I’d be very interested to know what is the pump threshold for supercontinuum in this setup (or the multimode setup). More specifically, how the input pump power relates to the output spectrum. Would you be able to measure this with some attenuators on the dye laser output? What I’m really wondering is if supercontiuum can be achieved with lower powers i.e. 10W and longer fiber lengths i.e. 20km (another standard telecom fiber cable length). Then a diode laser could be used to generate supercontinuum, eliminating the need for the dye laser and nitrogen laser. Let me know your thoughts on this!

I wonder how old single mode vs new single mode fibre changes things. The newer fibre is massively lower loss, obviously normally a good thing in transmission, but I wonder if that's actually worse here.

I suppose you'll need a daylight version of night-vision goggles to achieve true eye protection.

thats so ridiculously easy... actually I also have not any clue how this frequency shifts are done, maybe some intra-fibre-rerlections in combination with a low efficiency couple-out... its outstanding. i wish i could see the laser speckles in real life. about the donought, in the past i got pretty fine calculation results from WinLens3D, i guess somewhere in coupling-out you got some interference...

Is it possible to use a TEA Nitrogen laser ?

Cool. What was the inner diameter of the fiber

Is it possible to use this super continuum laser to perform stimulated raman spectroscopy?

Nice! How much the cable cost?

The beam seems unstable. What causes that?

I wish you explained why it works

What about a Q Continuum laser?

I like shiny things :p

but how you can be sure if this is really supercontinium laser? did you maked some experiments? I think supercontinium more than light source in VIS range

Yeah, *_"Price On Request"_* means DO NOT BOTHER REQUESTING...😊

I love your accent, it's like a 21st century Fred Dibnah 😊 This is incredible does it use much power and could it be used for lighting?

Isn't there some point where you have eliminated all the characteristics of "laser" light and all you have left is just mundane light? If this is a true continuum spectrum doesn't that mean the coherence length is zero?

You found a portal to simpsons dimension, that's the donut

I forgotten the name of the lense that is meant for intentionally creating that "doughnut mode", anyone care to remind me?

Supercont output doughnut due to interference effects?

Why not just use sunlight? (or black body radiation of something heated up a lot?)

How far are we from having white laser pointers at the same price-range as monochromatic laser pointers?

*listening at enhanced speeds* "...the work was done by Lenin/Stalin," Me: Pardon? *reads: 'Lin and Stolen'* Me: Ooooooooooh.

Laughing right now at how action lab thinking he accidentally found a super continuum laser before consider incandescence 😂

❤

sure is pink Floyd in here

what is this black magic

Dude!

omg