Attosecond Lasers (2023 Nobel Prize in Physics) - Sixty Symbols
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- เผยแพร่เมื่อ 8 ต.ค. 2023
- The Nobel Prize in Physics 2023 goes to Pierre Agostini, Ferenc Krausz and Anne L’Huillier "for experimental methods that generate attosecond pulses of light for the study of electron dynamics in matter". More links and info below ↓ ↓ ↓
Discussing the prize in this video is Ed Copeland, Mark Fromhold and Ioan Notingher from the University of Nottingham.
See our previous Nobel Prize videos at: bit.ly/SSNobel
And chemistry Nobel Prize videos at: bit.ly/periodicnobel
Nobel Prize website has more details on this year's prize: www.nobelprize.org/prizes/phy...
More on Ioan Notingher's work at: www.nottingham.ac.uk/physics/...
Ed Copeland: www.nottingham.ac.uk/physics/...
Mark Fromhold: www.nottingham.ac.uk/physics/...
Physics at The University of Nottingham: bit.ly/NottsPhysics
Visit our website at www.sixtysymbols.com/
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Sixty Symbols videos by Brady Haran
www.bradyharanblog.com
Additional animation and editing in this video by Pete McPartlan
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"We like working with lasers. They're really cool." That, my friends, is an honest scientist.
Finally, a fact about science that I can immediately understand.
You can put them together with ancient scientist,
They build the magic of chemistry, now is magic of lightning..
In soon we can time travel in attosecond speed..
They are giving prizes to destructions and addictions; learn about the story of your enslavement 👉The Connections (2021) [short documentary]💖
"... and lasers don't interfere with our samples ..." had me laughing
And this - people dickering around with cool stuff, or even just boring stuff - is how we advance.
1:52 "There are more attoseconds in a second than there are seconds in the age of the universe"
The scale of that blows my little mind.
The universe is older then he thinks. This makes his statement false.
@@Heinz-bx8sd i heard it started last Tuesday!
They are giving prizes to destructions and addictions; learn about the story of your enslavement 👉The Connections (2021) [short documentary]💖
@@Heinz-bx8sd Its actually 2023 years old!
@@Number6_how old is the universe in seconds? Is it not 4.36x10e7?
Very very good presentation. Feel smarter. For an atto-second. Then back to reality.
They are giving prizes to destructions and addictions; learn about the story of your enslavement 👉The Connections (2021) [short documentary]💖
I sometimes wonder if we could somehow tell Joseph Fourier what has been accomplished in his field, what he would think.
His response: "Really? That's it?"
He's really made waves in the world of science.
@@vigilantcosmicpenguin8721You. Take my like and get out.
They are giving prizes to destructions and addictions; learn about the story of your enslavement 👉The Connections (2021) [short documentary]💖
@@vigilantcosmicpenguin8721 😂
The more you know about the duration of a pulse, the less you know about its frequency. Attosecond pulses don't have "a" frequency, but are actually the sum of an extremely wide band of frequencies. Which in turn means scattering at the target, where the pulse doesn't "bounce" off of an object, but instead "splashes" against it/them. Which in turn means detection is really tough, even without hitting a target, which I feel helps to explain why experimentalists won this Nobel. The detection aspect alone is worth a deep-dive video of its own!
In the early days of my own work, I had to measure and calibrate instruments to accurately read over 10 decades of current, from 10 milliamps (10e-2 amps) down to below 10e-12 amps (single-digit nanoamps), which meant detecting currents at least an order of magnitude lower (preferably 2) at the tens and hundreds of femtoamps level, which is getting aggravatingly close to counting the rate of flow of individual electrons. (Well, sometimes not the rate of flow itself, but extremely low currents, the interarrival times of electrons into the lab equipment.)
The hardest part was making sure I was measuring what was actually desired, rather than noise from a very large number of other possible sources. Which is a whole 'nother story.
The signal-to-noise ratio is a fundamental buggeration in a lot of scientific & technical areas.
My field was environmental science, & I dabble in music-making & sound-recording.
2 entirely unconnected subjects where I've had to deal with it. :)
Single digit nano is 1e-9, my guy.
i worked out Ed Copelands formula on the whiteboard, it's the original Cherry coke recipe
It’s very distracting! 😅
Sounds like the cherry on the top
I'm always a little bit surprised to hear how excited scientists are when their colleagues win the prize. I'm sure they are very competitive at times, but it's really refreshing to see the collaborative effort that science can be. epic stuff that I'm sure will bear fruit in the future. I never miss sixty symbols, just the best!
They are giving prizes to destructions and addictions; learn about the story of your enslavement 👉The Connections (2021) [short documentary]💖
nithya gandhi
I think this happens because the importance of the prize is less about money or fame going to individual scientists and more about public attention getting directed toward fields of study that scientists know are really cool, but that most regular people don't spend much time thinking about.
@@VeganSemihCyprus33 if i see this cut and paste once more i'll report spam.
That is because any groundbreaking work in their field can be immensly helpful to their own research in so many ways. ON top of that it puts a spotlight on their area of science, which makes it easier to gain grants, makes more students interested in your specific field etc. etc.
“Are you happy for Pierre Agostini for getting the Nobel Prize?”
Mark: “Agosti-no”
They are giving prizes to destructions and addictions; learn about the story of your enslavement 👉The Connections (2021) [short documentary]💖
@@VeganSemihCyprus33 ???
Exactly, like Gigi D'Agostino. :)
@@VeganSemihCyprus33 YAY! 😊😊 Learn about your enslavement today 👉 --- 💖💖💖💖
😂
Mark Fromhold is so annoyed about Pierre Agostini getting the Nobel Prize instead of Paul Corkum that he gets Agostini's name wrong twice.
I mean, fair
They should put some corrections on this video, but only after Agostini gives some kind of public respect on the efforts of Corkum on this =D
Paul Corkum certainly contributed a significant amount of work to attosecond physics. I would also point to the common misconception that his team was the first to explain the mechanism underlying attosecond pulse generation. The Nobel Committee correctly detailed that Kulander et al. defined the rescattering model at the same time as the three step model (and actually published before the three step model).
@@timothygorman3691
In my opinion, the fact that the mention of every single individual mentioned in this video should be followed by “et al” (as you did in your reply) underlines the silliness in looking to name individuals for these prizes any longer.
@@briandeschene8424 I think that there need to be some rule changes to allow the prize to be given to teams as well as individuals, or they perhaps ought to create a separate set of prizes for teams. As has been mentioned multiple times in this comment section modern science is frequently done by teams and incrementally by people who add to our knowledge over time, sometimes without even meeting each other. Three people is now too few and I think a consensus is building behind the need for some sort of rule change in that area.
I've heard "There are more attoseconds in a second than there are seconds in the age of the universe" a few times, but there's also more Planck times in an attosecond than there are seconds in the age of the universe.
Yes, yes, but let's try to not 🤯 everyone at once.
Well, there are more Planck times than a lot of things.
They are giving prizes to destructions and addictions; learn about the story of your enslavement 👉The Connections (2021) [short documentary]💖
@@PeterBarnes2most of things actually.
Now you're just showing off. ;)
Excellent explanation! I always love Copeland's explanations.
WOOOOOO
They are giving prizes to destructions and addictions; learn about the story of your enslavement 👉The Connections (2021) [short documentary]💖
@@VeganSemihCyprus33 get!
Begone, fake prizes spammer!
I remember being invited in 2003 to witness experiments that tried to take these ultra short laser spectroscopy shutter takes of interactions between atom clusters, but back then they only managed to reach femtoseconds, not attoseconds, which, considering what they were trying to look at, was precise enough. I'm astonished they actually reached scales to see the movement of individual electrons now, SUPER! B)
Did they actually just exploit quantum leap to turn it into a laser 🤣🤣 leveraged uncertainty ! why fear the unknown embrace it this is how we win.. brilliant
Professor Copeland is always a joy to listen to.
what a clear and easy to grasp explanantion, i avoided this video cos i thought it was hype, but so glad i found this guy.
I'm not sure what it is about him or his voice, but I could listen to Professor Copeland talk about Physics for hours (and I have lol).
@@TheHackysack his soothing voice and excitement to discuss physics is what brings me back. I regularly put on a playlist of Sixty Symbols videos that he has appeared in when I'm going to bed. It helps keep my mind from racing and I can actually fall asleep. And I might actually be absorbing some knowledge while I do it lol.
"I have walked across the surface of the sun. I have witnessed events so tiny and so fast, they could hardly be said to have occurred at all."
The Nobel Prize really is the Oscars of academia. It has the same benefits, of rewarding great achievements, motivating progress, and bringing it to the public's attention. But it also has the same problems, with bias in the committee, and controversy over who deserved to be picked, which often ends up detracting from the achievements made.
It goes way beyond bais in the committee. The whole thing only awards prizes in five specific "genres". It's not like the Oscars committee saying "Eh, none of us is interested in French womens' basketball, so we're not giving a prize to this movie." It's at the level of "Sports movies are not eligible: we only do historical dramas, comedy, action and science fiction."
I am taking a semester off my physics studies due to several stress related mental illnesses. I've avoided any type physics relateded media because it just made me feel stressed out and sad for like a year now... man maybe the therapy is working after all! I hope I can get back into the groove sooner rather than later and finish what I started.
Don’t give up. Never quit.
@@canadiangemstones7636 that type of thinking got me here in the first place lol. It's more like "quit when your brain is screaming so loudly for you to TAKE A BREAK before it forces you to take a break" lol
Sounds like things are getting better for you. I hope that continues. Time can certainly help.
Taking a break is not giving up. You are taking care of yourself. I think that's the opposite of giving up
“There are more altoseconds in one second than there have been seconds in the age of the universe” is just mind boggling to think about.
Amazing work but let's not forget the 2023 Ig-Nobel prize for Physics which went to Bieito Fernández Castro, Marian Peña, Enrique Nogueira, Miguel Gilcoto, Esperanza Broullón, Antonio Comesaña, Damien Bouffard, Alberto C. Naveira Garabato, and Beatriz Mouriño-Carballido, for measuring the extent to which ocean-water mixing is affected by the sexual activity of anchovies. Nature Geoscience, vol. 15, 2022, pp. 287-292.
Do you know how many anchovies there are, & how much of which oceans they occupy? :)
@@DickHolman A truly ponderous question... perhaps the answer is buried in the research paper? ... my back of the envelope calculations suggest the answer is "Lots" and "Lots".
@@daz4627
:D Lots² is about right.
Some Ig-Nobles make you go "They WHAT?", but when you look at the larger field they make sense.
Mostly. :)
Wonderful video. And a huge wow to this professor able to come back to our modest levels and make us understand the basics !!!
Thank you
Was waiting on this! Always love watching this series
I never read anything about the Nobel prize winners. I just wait for the Sixty symbols video.
They are giving prizes to destructions and addictions; learn about the story of your enslavement 👉The Connections (2021) [short documentary]💖
Fourier series always turn up in the most unexpected of places.
I went to U of Ottawa in physics and i graduated the year Paul Corkum moved from the NRC to uOttawa. When i heard the Nobel prize was for attosecond lasers i thought it was for him too.
I remember hearing the explanation in school of how light wavelengths meant we couldn’t see past a certain scale, it’s so cool to realize we have advanced beyond that level!
The entire concept of stacking waves to make smaller pulses seems like one of those ideas that's so simple that after someone figures it out that I bet many a physicist are slapping their forehead saying "Why didn't I think of that!?"
When i first heard about the prize and the research, i literally went “what?” Thats too simple how did that win?
It isn't like physicists didn't know this or think of this concept before but you need quite powerful and stable femtosecond lasers to do the experiments Ed describes in order to achieve such high electric fields that they compete with that of the nucleus of the atom. These lasers weren't properly developed until the last 2-3 decades of the 20th century.
They have been thinking about that for over a hundred years. And every modern device you use that communicates are using this principle. The difference is that they reached a limit of how small wavelenghts it was possible to produce since light has a finite wavelenght. The price if for a novel way of producing smaller wavelenghts by exiting electrons that then radiate their energy in form of shorter wavelenghts.
IKR. 😅😅
Brb. Going to vibrate some lead weights to create femtosecond gravitational pulses.
This is extremely advanced physics, but still I think I can generally follow along with the basic principles behind what's being done.
I so much enjoy Prof. Copeland's explanations.....another excellent learning video.
This is hands down best video on this topic explained in easy, but reasonably comprehensive way
17:28 "We like working with lasers because they are really cool" couldn't have said it better myself!
Brilliant video with insightful explanation ! (Some of my handwritten equations are on Ed's whiteboard :-D).
This is not the first time I've heard a criticism of the Nobel limit of 3 people sharing the prize. Given that a lot of modern science is more complicated and has more contributors than ages past when just figuring out that a lever was a useful tool was fancy, might they consider adding more people in the future or expanding the list of names even if they don't widen the prize itself?
Thank you for that clear explanation
22:33 "we give a lecture based on the nobel prize for picosecond lasers" also "this little box here is an off the shelf laser that i use for my work" - that's technological progress - from "amazing -> its worth a nobel prize" to "lets google a supplier for a component"
Mind-blowing stuff! 🤯
Extremely interesting! Thanks for this video!
I have so many questions! How tightly locked is the phase of the outgoing pulse train? Could this system be used in photolithography?
Would love to have you post again man!
These videos really create more questions than they answer. Only makes me want to dig deeper!
They are giving prizes to destructions and addictions; learn about the story of your enslavement 👉The Connections (2021) [short documentary]💖
There is no reason to use this light for photolitography because for a transform-limited pulse (best case) the spectral width is very large. A picosecond is (much!) smaller than an oscillation of the EM field at visible wavelengths, to give some intuition about this. It is however amazing for pulse-probe schemes, as explained in the video!
@@mio_qo Thank you. I figured there had to be downsides of generating things in this way.
Oh hi, Prof. Fromhold! Good to see you! I was just reminiscing about being in your tutorial group the other day.
hi , not a professor since the 23 December 2013
@@georgen9755 I appreciate your commitment to factual accuracy. He'll always be my professor 🙂
The 2018 prize was also for ultra fast laser pulses. This field is getting a lot of love recently.
It was for CPA, an amplification method that allows pulses to reach ultra intensities, but yes it does fall into the ultra fast category.
I can feel happyiness of this man. This is the way we all should do our works and feel, find what make you feel like this and go for it.
Man, CD players are going to be amazing when this hits the market.
Unironically. This type of stuff matters for semiconductor research. An ssd is conceptually just a modern cd.
What a great explanation of such a complex topic
The Nobel event, could easily create a new division. A Nobel prize for a team.
Prof. Agostini did his work at my alma mater! O-H!
Another awesome video. Thank you so much.
Great video. And I was happy to learn the origin of the name Sixty Symbols in the 3 Bean Dish Quiz! :)
those are two amazing achievments both cheating out more energy than usual out of an electron in a gas and creating pulses with wavelenghts shorter than the constituant waves
This brings back memories of third-year chemistry lectures, in which the lecturer was trying to get undergraduate brains to grasp the concepts of polarisation and charge transfer, as stages in the progress of a chemical reaction.
Now they can measure that polarisation of an atom . . .
Great explanation as always😊
Thanks for this channel for checking what the science news is in real life
The layering of frequencies sounds a lot like FM synthesis. 🤯
Measured the echo nice work 👍🏽
Suoer explanation! Many thanks!
This is not the first time physics committee of nobel did not provide it to the one of the key actor. Bose being one extraordinary example.
theres a limit of 3. unless it was done by an organization.
I think they got the prize for finding the most complicated way to have a short burst of laser light, rather than just switching a normal laser source off and on very quickly.
Superb video, thanks to everyone who contributed.
Just when I thought femtosecond lasers were the coolest thing to ever have existed, attosecond laser gets invented.
as for theoretical physics/cosmology uses of such a device.
building programs that would allow us to build a better picture (we are a visual species) of
the inner workings in the earliest moments (attoseconds) of the universe.
and from there, to scale up to...well, universal sizes.
Great explanation.
16:30 GREAT! TEAMWORK 🎉❤
CHANGE THE RULES🎉
Truly amazing! 💯🫡
i hope you see this comment and reply. Could you do a video interviewing some of these scientists and others about how they do research and planning their work (their strategy)? Thanks!
As David Bowie once wrote: Give me steel, give me steel, give me pulses unreal
Thank you!
Proud to be a former student of the Atomic Physics Department in Lund. Studied medical applications of lasers under Sune Svanberg et al.
In audio we call it additiive synthesis. Greetings from New Mexico!
Amazing!
About the question on a short pulse into the eye: It seems to be pretty much a question of duration x power trade-off. As I understand it, we'll detect almost arbitrarily short (weak) pulses if they are powerful (long) enough.
I think it's a bit more complicated than that. The photosensitive chemicals in the rods and cones in our eyes need a minimum of seven photons of sufficient energy to strike a molecule within a certain time period to cause it to trigger a signal in the optic nerve. That means there's a range where the attosecond pulse has to deliver the right amount of energy, so it can't be arbitrarily low or arbitrarily high. Even then, there's no guarantee that our brains will recognise that signal, because there'll be a threshold there too.
Having worked in an attosecond lab:
- The attosecond pulses are not visible because our eye cannot detect the wavelength. Also as @RichWoods23 suggested, they would probably be to weak to be seen anyways.
-But visible-wavelength femtosecond pulses (1000 attoseconds, so still way to short for the eye to resolve) can absolutely be seen. We shoot such a pulse 100 to 1000 times a second so to our eyes it really looks continuous.
However if the pulses hit some material it heats up and expands a bit for each pulse. This creates a regular pressure wave so basically sound. So we hear this humming noise whenever we hold something into a focused beam.
Mark is probably thinking of another great mind of our times, Gigi d'Agostino
😂
thanks!!!!
locating an electron just remembered me of my favorite science joke:
Heisenberg driving in his car gets stopped by the police.
the officer asks him: "do you know how fast you were going? 180 miles per hour!"
and Heisenberg answers: "great! now i have no idea where i am!"
Best slow-Motion camera ever made
15:19 a more interesting question is how would an atom behave if it has it's electron held still @sixtysymbols
Thank you.
The explanation from Prof. Copeland of the additive technique for generating shorter light pulses is so simple and so clear at the same time...
Hajrá, Feri!
THANK YOU SO MUCH!! I had never even heard of an ATTOSECOND before seeing this video... but I had heard of a pico and nano second before tho ... So when the Professor in the last part of your video compared an attosecond as 1 second then a picosecond would be 2 weeks, I nearly fell off my bed!!! That REALLY hit home as the the scales of time these geniuses are working at... it's mind blowing!!!
THANK YOU ONE AGAIN BRADY!!! Keep up the amazing work!!!
This would be very interesting for observing chemical reactions. Wonder if it could be used to make up processes for making new materials etc
Wondering that too. How much of a leap between 'measuring where it is' and 'forcing it to be where we want it'.
Will this be a stepping stone to become able to 'weld' atoms together in stead of pushing them together and hope for the best.
From what I recall, femtoseconds tell you a lot about the transition states of chemical reactions. (See: 1999's Nobel Prize winner in chemistry, Ahmed Zewail.)
@@DreadX10 Quite hard, because to combine two atoms you need the atoms to be near enough to one another at the same time the laser pulse arrives. Even then you need to create conditions that are energetically favorable for the atoms to combine. If you knock off electrons from the atoms, for example, you create two ions that repel. You might be able to change the state of the valence electrons so that in each atom you have an unpaired electron and so that there is an attractive force, but if it's not a ground state configuration, it is unstable.
If you can make these pulses and then alter them you can then create code within the pulses that you can decode, you could download the whole internet in a second? I'm thinking of like uses long term. Lasers already transmit light to power broadband rather than the electric DSL stuff
just a question. would it be possible to trace a single electron in a way where you have a detector at 2 points that are able to measure its location?
in this way you know the exact location of an electron at 2 points in time and with that calculate its speed or does the electron like, fizzle out of existence upon exact measurement?
Waiting for this, since the moment they announced the award
What an accomplishment, I only hope I have enough attoseconds to understand this fully😭
Love Ed Copeland's footie goal.
Is it gonna change Heisenburg's Principle related to Time and Energy?
How are such time scales measured? I would like to dig deeper into that rabbithole. How does one confirm the attosecond pulses and how is this measured? Also, does a short pulse of light mean, that the wavelength of that pulse is as short as the pulse and is therefore so energetic or am I misunderstanding the way such short pulses work?
So this means the pulse isn't like a conventional laser pulse which is made up of multiple oscillations, but it's instead a literal single electromagnetic impulse. I'm curious about the implications of this, as it's far removed from how I usually think about EM waves.
If it's x-rays then it will have multiple oscillations, but there are "few cycle" or even half-cycle laser pulses, where the pulse duration is the same duration as a half cycle of oscillation.
An X-ray period (say one angstrom wavelength) is 10^-19 s whereas an attosecond is 10^-18 s.
That's pretty awesome.
I’m holding out for Yocto and Planko. Honestly, as important as atto- is, it’s the method that now paves the way to many orders of magnitude smaller. Can’t wait till we can see life on these fundamental particles and realize it’s all a repeating fractal 😂🤣😂 on infinite scales.
So it's a timedependant orbitalgeometry at specific points of time (attosecond shut)? thats how i would understand, if they are watching for the peak amplitude to "locate" the highest probability of the electron around the nucleus.
could attoseconds help fix the floating point rounding issues with modern computing?
I think this could be useful in particle physics. Studying some particles with very short halflifes.
There are 892 elementary particles with lifetimes less than an attosecond. There are even 15 particles with a lifetime of less than a yoctosecond, according to Wolfram Alpha.
So for certain particles, an attosecond is very long. But for most, it is short enough.
soliton physics !
Small corrections: First, the characteristic wavelength of the incoming primary light 10E-6 m, not 10E-15.
Second, "ordinary" femto second lasers also use the overlapping wave principle, so this is nothing new. However, they cannot reach these extremely short pulse lengths, because there are no laser media available to cover the necessary frequency spectrum. For instance, titanium sapphire crystals "lase" from about 700 nm to 1000 nm, so if you build a femto second laser with that, you have these 300 nm range to play with - which is quite a lot, but not enough to go to 10E-18.
Fantastic stuff. Also i want to emphasize what Mark Fromhold said about teamwork in science. That is exactly the reason why i love working in a scientific enviroment. It's the international cooperation where we try to leave out all political and religious tensions and work on one big goal. I like to think in a way great humanists like Isaac Asimov described it as "projects for world peace".
Agreed. It is also why it should be possible to award Nobel Prizes to more than three people IMHO.
Attosecond computing. I'm waiting!
Looking at the spatial side, if the duration of a pulse can be made to span mere attoseconds, how small can the area of the "face" of that pulse be? Does pulse duration affect how much we can focus the pulse?
*mere _hundreds of_ attoseconds.
Well kind of...
The pulse duration does not affect focusing properties directly.
But to reach these short pulse duration, we needs very short wavelengths. And shorter wavelength does indeed enable a smaller focus.
@@marvinschmoll2648 you seem to know a lot about this topic...
Wait, so does this mean that we can do Fourier series with real matter? When you think about it kinda has to work in the real world to, not just mathematics, but it's still mind blowing.
I feel like a phased array is something akin to a 3 dimensional Fourier series and that's a tech that was done in the 2nd world war.
Ok maybe this is a dumb question but if you can exactly pin point the location of an electron and then exactly pinpoint its location a fraction of an attosecond later, couldn’t you calculate its velocity with that information? Would a sub-attosecond frame rate then violate the uncertainty principle?
Incredibly clever work, excited for physical chemistry applications as mentioned
Is this an avenue for much higher powered lasers?
Maybe more powerful computers? comptuers all run on crystal oscillators pulsing at a certain speed, if you can pulse with atosecond pulse lenghts that should speed thigns up dramatically. Maybe used with the new light computers that could handle these osiclliating speeds, because im not sure traditional transitors could. But im thinking more practically it will be used to measure things, if you have that kind of pulse resolution, you can probe small things in time, or run things really fast. Im just speculating im not an expert, but in my recent work with microncontrollers, im learning the CPU uses pulses everywhere, for timers, everyhing, its resolution / speed ultimately depending on the time delay between pulses, the heart of the CPU is the oscilliator,and this could be a next gen one.
Yes!! I did my masters on this! This is going to be a bit long winded but I haven't got to talk about this stuff for ages :)
TLDR; Since power is energy over time - as time gets shorter, power increases (if we can keep energy high). There is theoretical work that shows that the relativistically oscillating mirror method can take us up to 1E29 Wcm-2!! At this energy quantum electrodynamics predicts the vacuum itself breaks down and forms electron positron pairs spotaniously. At this energy the vacuum is also expected to refract light depending on polarisation and direction of travel. Mad lol
---
After this work on gases, another method that uses relativistically oscillating plasma mirrors was developed (ROM)- Ionise a surface with a pre pulse and then shine a powerful femto second laser at it. The EM field couples with the free electrons in the plasma, they line up along the incoming wavefronts. This electron surface acts as a mirror since the electrons align themselves to cancel any field incident on its surface.
The electrons move with the field and so the mirror moves back and forth as the field switches sign. This motion is fast - very fast and is dependant on the frequency of the incident radiation. As the mirror approaches the speed of light its gamma coefficient spikes. Contained during these spikes, non linear optical effects lead to the generation of harmonics of the incident laser pulse. Incident radiation is shifted up proportional to 4gamma^2 . These harmonics then overlap just like in the video and we get the same train (only more efficient).
There's a lot to like about the mirror method. First of my masters was on shaping the incoming pulse, if you can make the mirror move faster, then you will generate higher harmonics and therefore your pulse can be shorter and more efficient. So use multiple colours with their phase alligned and you can double the efficiency!. There is no limit to pulse intensity like there is in gas harmonic generation, after a certain threshold the mechanism discussed in the video no longer works. This does not apply to the mirror. ROM generation is also more efficient at baseline. So more energy from the original pulse is deposited in the train. The emitted radiation is also diffraction limited so is incredibly well focussed and coherent. We love to see it :)
@@mikejones-vd3fg idt a faster oscillator is what's needed here. the issue with that specifically is the amount of heat that computers give if you have them run too fast (this is why room-temperature superconductors would be huge breakthrough).
@@gloo0m this is incredibly promising! Are there any specific publications you recommend regarding this? Ah all the phenomenon we can explore at such small scale, high energy densities!!
I don't think I've been this excited for a nobel in years
@@alicewonder259 The main paper I'd recommend for more of an overview of small-scall, high-field physics (rather than the great engineering work described above) are a progress article (by Corkum and Krausz in Nature): 10.1038/nphys620
There's also a whole set of other related topics to this: high harmonic generation, strong field ionization in general, quantum control, and molecular movies. I'm must admit I'm a bit biased - currently doing my PhD in the field...
In Anne L'Huillier's ealry work on this, is it important that the incoming laser is infrared and the gas is helium (inert gas)?
Wouldn't the same effect occur in general laser-matter interaction?
For the laser:
Looking at the explaination around 6:00:
IR is used because its wavelength is longer than that of visible light. This means that it also takes longer for the direction of the electric field to change. Therefore the electron has more time to get accellerated and will gain more energy.
For the gas:
As far as I am aware Neon was just used because Noble gases have a very simple structure.
By now many other gases and materials have been studied and the effect also works.
Could attosecond lasers eventually be used to determine precisely both the position and velocity of an electron thus contradicting the Heisenberg uncertainty principle?
I wonder if we extrapolate that idea a bit further: lets say you take a fairly typical area. There are many signals and wavefunctions flowing through our airspace all the time -- AM, FM, XM Radios, GPS signals, Telecommunications equipment (4G LTE, 5G), Radar, Lidar, Satellite Data (internet, weather, maps), etc.
In theory if one had access to these wavefunctions (data streams), could one render a 3D object using the interference data? ;)
5:59 What they're showing is a standing wave, not a propagating wave.