The 3 Strongest Lasers in the World (For Now)

You know, I miss when we used to answer Patreon questions on Scishow. In fact, I have a list of them. I’m gonna just take out my phone and I’m going to pick one at random. “Dear Mr. SciShow, I just got promoted to head-henchperson (cool) for an aspiring supervillain. The department heads just got out of their weekly Evil Pitch Meeting and my boss would like to hold the world ransom with the world’s biggest laser. I need the plans on his desk by Friday. Please help. Love, H. ” Well, H, this definitely wasn’t an invented bit. Let’s see what SciShow can do for you. Here are a few candidates for the worlds strongest lasers. This is exciting, I can’t wait to find out more. [♪ INTRO] Now we have to figure out what a laser even is. Your boss might be looking to Hollywood for examples, where the word might be used to refer to any beam of energy, like what Superman shoots from his eyes. Or cyclops, but everybody knows that’s just “punch energy” from the Punch Dimension — it’s not a laser. The word laser is a technical term for a specific thing. In fact, the word is an acronym: Light Amplification by Stimulated Emission of Radiation. And that tells us that lasers are a kind of light. Often, the same electromagnetic waves that we use to see the world. But there are also light waves humans can’t see, like infrared radiation and x-rays. And we can make lasers emit that kind of light, too. That’s right, we can make X-ray lasers! Sounds very dangerous! The rest of the acronym tells us how lasers produce light. Specifically, by forcing atoms to emit light much more readily than they usually do, hence words like ‘amplified’, and ‘stimulated’. And that light is emitted in a very particular way, using the laws of quantum mechanics to ensure that only one wavelength of light…one color…comes out. Lasers can also be super concentrated, only travelling in one narrow beam. That’s why the beam of your laser pointer is invisible from the side, unless someone has recently clapped two chalkboard erasers together to fill the room with a bunch of teeny particles for bits of the laser beam to bounce off of. Ultimately, lasers produce light that you can tune to flow down one precise channel. You can also control its exact color and the amount of energy the beam carries. Easy to see how this could be useful in lots of circumstances… even if you are not an aspiring supervillain. Since they were invented in 1960, lasers have found uses in everything from barcode scanners, to eye-repair surgery to fundamental physics research. So with that background out of the way, because we actually want to be talking about lasers when we’re talking about lasers, let’s talk about what the current strongest lasers in the world are. We’ll start with the most powerful laser. And that’s actually a technical term. In physics, power refers to energy per unit time, usually measured in the unit watts. One watt is a joule of energy that’s used or released over one second. And one joule is roughly the energy you need to pick up a small laptop. The “per unit time” bit is also important. A laser can be made more powerful by emitting the same amount of energy in a shorter amount of time. A typical laser pointer will emit a few milliwatts of light, one-thousandth of a watt. The most powerful lasers you could plausibly buy emit kilowatts, thousands of watts, so about a million times more power, and those lasers are used in industry for welding metals together. You are not gonna get them on Amazon. Also be careful, we do not condone the purchase of dangerous lasers. Cause yes, even supervillains should follow lab safety protocols. So here we should stress that even low-power lasers can be super dangerous. One would never, for example, point them in someone’s eye. So the question becomes, how powerful can lasers get? To go more powerful than the kilowatt scale, you need to go to a pretty advanced physics lab. But it turns out that the most powerful lasers in these labs don’t fire continuous beams. Instead, they emit laser light in short bursts, called pulses. And by “short” I mean, well, some labs can achieve pulses that last a few quintillionths of a second, which are called attoseconds. These attosecond pulses are hugely important for modern physics, and won their developers a Nobel Prize in 2023. Because the pulses are so brief, such a laser works like a high frame rate camera. A like super duper high frame rate camera: it can even let researchers see electrons moving around inside atoms! This trick works by using the rules of quantum mechanics to combine laser beams at multiple different frequencies. So unlike with a laser pointer, if you could see the light from these ultra-short pulses (which you couldn’t, but if you could) it wouldn’t appear to be any particular color. Supposedly, the current record holder for highest power in a laser pulse is located at the Extreme Light Infrastructure facility in Romania. Although, we should point out this record is disputed by other labs who have staked their own claim to the superlative. We’ll be getting to one of those lasers, later. A laser at the ELI can produce ten petawatts of power. That’s one trillion kilowatts, and one quadrillion joules per second. It’s quite the punch, although no one’s using it to hold the world hostage.

Over the years, hundreds of different experiments have been done with this laser, in a number of scientific fields. Like, researchers have tested biological sources’ exposure to radiation for cancer research, studied fundamental nuclear physics, and re-created extreme astrophysical scenarios for cosmology research. But because their pulses only last for tiny amounts of time… just a few thousand attoseconds…each pulse only emits a few joules of energy. So as powerful as these kinds of petawatt lasers are, your evil boss is going to be disappointed. They’re not especially energetic. But there is a laser out there that emits way more energy, even if it’s also over a relatively short amount of time. And we’re gonna tell you all about that, after this break. This SciShow video is supported by DeleteMe, the hands-free subscription service that removes your personal information from hundreds of data broker and people search sites. And not just your info. DeleteMe has been the leading expert in personally identifiable information removal for over 15 years and was recently named the #1 data-removal service by Wirecutter. So lots of people trust them. Like our executive producer, Nicole, who signed up this year! She said they’ve already reviewed over 900 records and begun removing them. And when she says “they,” we’re talking real people available for custom requests and help when you need it. To sign up for their service, use the QR code on screen or go to joindeleteme. com/SCISHOW and use promo code SCISHOW at checkout. You’ll get 20% off DeleteMe US consumer plans. In the small California town of Livermore, a research facility is trying to harness the power of the Sun. The National Ignition Facility, or NIF, is a prominent figure in humanity’s race to produce a commercially-viable form of nuclear fusion. It’s basically the opposite of nuclear fission, which is how modern nuclear power plants source all of their energy. But pound-for-pound…or since this is SciShow, kilo for kilo… fusion releases way more energy than fission. And depending on the kind of fusion that you do, it doesn’t leave you with much, if any, harmful nuclear waste. So it would be great if we could figure out a way to make nuclear fusion work that isn’t just “let the Sun do it’s thing and then use solar panels to absorb a tiny fraction of the energy that eventually reaches Earth”. Unfortunately, achieving any amount of nuclear fusion, let alone doing it in such a way that you can get more energy out than you have put in, is ludicrously difficult in practice. People have been trying for decades with no success. It requires you to pump an unbelievable amount of energy into incredibly tiny spaces, to push particles extremely close together. While scientists around the world have tested a variety of techniques, NIF achieves this extreme energy density by shooting ultra-powerful laser beams at tiny pellets of nuclear fuel. It takes a single ultraviolet laser beam and splits it into 192 smaller ones, each of which is then separately amplified up to monster energies. Those beams then hit the pellet from all sides, squeezing the fuel particles together. Like the laser at the ELI, the NIF lasers only emit light in super-short pulses. Though here, we’re talking about nanoseconds: about a billion times longer than before. But the real difference between these two setups is in the energy scale. A typical pulse at the ELI emits a few joules of energy, but a typical NIF pulse emits millions of joules. In fact, there’s a joke that NIF scientists like to tell about how much more energetic the NIF laser is compared to its peers. And it goes like this: “What’s the strongest laser in the world? The NIF laser. What’s the second reflection of the NIF laser. ” Cool folks over there — not nerds at all! Which is to say, any random stray laser light bouncing around inside of the laser chamber is still far more energetic than any other laser in the world. And yeah, that is what passes for humor among nuclear physicists… It also gets brought up by NIF tour guides. In 2022, NIF reached a key milestone in nuclear fusion research called ignition, where the fusing material emits more energy than it absorbs: three megajoules out for two megajoules in. However, there’s a super important caveat, here: that “two megajoules” is only the energy that went directly into the fusion pellet. It does not account for all the energy needed in the laser chamber, which can be hundreds of times greater. So humanity is still a long way off from building a proper nuclear fusion power plant. And I would personally recommend to any supervillains with a giant laser at their disposal to help conduct nuclear fusion research that everyone can benefit from, rather than holding the world hostage. If NIF’s ultra-high energy laser doesn’t impress your boss, then here’s a nice backup plan: the highest intensity laser in the world. See, one factor we haven’t mentioned yet is how focused the laser beams are. Each of the lasers so far has been able to dump its energy over a very short period of time, but each can also dump the energy into a very tiny area. This is the intensity: how much energy is emitted, per unit time, per unit area.

It’s usually measured in watts per square centimeter. Basically, it tells you how concentrated the laser energy is. And once again, we’ve got some pretty big numbers to consider here. In 2021, a milestone breakthrough was achieved at the Center for Relativistic Laser Science in Gwangju, South Korea. Like other cutting-edge lasers around the world, this one achieved a few petawatts of power. But by focusing that wattage onto just a few square micrometers… an area roughly the size of a bacterial cell… the laser achieved a record-breaking intensity of 10^23 watts per square centimeter. That’s roughly 100 zettawatts per square centimeter, if you want the fancy jargon. And this wasn’t just to break a record, of course. Not that scientists don’t like breaking records. In lots of fundamental physics research, energy density is the name of the game. Some strange phenomena only happen when you pack enough energy into a really small area. For instance, if the laser’s intensity is high enough, an electron within the beam’s path can absorb multiple light particles at once. And then, that electron can emit a single light particle with hundreds of times as much energy. The hope is that those super energetic light particles can mimic the effects we see in extreme astrophysical situations, like the magnetic fields around black holes. It’s also thought that at even higher intensities, we might be able to see different properties of the vacuum, of empty space itself, because empty space isn’t actually empty. But we’re not quite there, yet. In the years since 2021, other laser facilities have claimed they too can go past 10^23 watts per square centimeter. So the fight for the title of “Most Intense Laser” continues. But maybe that boss of yours doesn’t like any of the options available right now. Maybe they’re the patient sort. So what lasers might be available in the next several years or so? Well there are a few facilities under construction around the world that intend to utterly blow the current record holders out of the water. In the UK, there’s the Central Laser Facility’s Vulcan laser, which is currently getting a major upgrade called Vulcan 20-20. That’s due to go online in 2029. The 20-20 name comes from their two main goals: to upgrade the beam from one petawatt to a record-breaking 20 petawatts of power, and to produce beams with 20 kilojoules of energy. It’s not because they thought they were going to be done in 2020… which would be funny but it’s not. But the’re not going to be able to do those 2 things at the same time. The 20 petawatt beams would have about 400 joules of energy, and the higher-energy beams would have less power. Vulcan 20-20 also hopes to reach an intensity of 10^23 watts per square centimeter, to test the Unexplored physics at those energy densities. But as ambitious as Vulcan is, it’s nothing compared to what they’re building in China. At the Shanghai Superintense Ultrafast Laser Facility, (Super intense and ultrafast?! ) researchers have already claimed to hold the current power record, and are building something even bigger. The new facility, which is called the Shanghai Station of Extreme Light, is intended to house a 100 petawatt laser in the next few years, which would be the undisputed king when completed. With ultra-short pulse times, and super high intensities, this thing could rip the vacuum apart, creating cascades of subatomic particles in never-before-seen ways, mimicking the highest-energy astrophysical events and unlocking untold new physics. And we will just have to wait and see what actually happens. We definitely will cover it, I promise. As cool as these super lasers are, none of them work as some kind of death laser that would help an aspiring supervillain take over the world. But there’s also clearly a market for building bigger, better, fundamental physics-understanding lasers. So if the head-henching ever seems to not be working out, I have a great alternate career path for you to consider. Just something to think about. [♪ OUTRO]