Dangerous tattoo remover from eBay is a MILLION watt laser

I recently purchased this Chinese-made

laser

tattoo

removal device on eBay. Now, according to the specs, this thing should contain a really scary pulsed

laser

system inside and if so, I'd love to play with it when it comes to eBay wacky gadgets like. You never know what you're going to get. For one, sellers often lie through their teeth about qualifications, and for another, this entire system costs less than having a doctor burn a

tattoo

, so it's not like you can expect a state-of-the-art medical system. That said, I'm not too worried about how safe or effective this is because, honestly, I just want to blow up some things with a pulse laser.

In fact, if this can produce pulses of, say, I don't know like a

million

watt

s, I'll be pretty impressed, and if not, I'll have to give it some much-needed upgrades. So yeah, without further ado, let's turn this on. So, spoiler alert. This thing has some serious firepower. See all those little marks on the screen? This thing is so powerful that it put a lot of holes in my camera sensor without even taking a direct hit. My point is that this is definitely not a toy, and as tempting as it may be, I don't recommend buying one of these things.

Dangerous is an understatement for this laser and if you don't have high end laser glasses you will go blind using this thing. So yes, please don't try anything you see in this video at home. Well, this is what comes with this unit. You have the laser head here and the main power supply. I got these tips specific to treatments that could actually change the laser output color. you have this really mysterious ointment, this funnel to add cold water, a foot switch, and then these really sketchy laser glasses. This manual here, if you can call it that, turned out to be completely useless in assembling this thing, but fortunately putting this thing together was very simple, like honestly a ten year old could assemble this thing, and I'm not entirely sure that that's a good thing.

I went ahead and used deionized water for the cooling fluid, since it turns out that ultrapure water is actually a very, very good electrical insulator. very good right? Now before I turn on the laser, I need something to protect my eyes because from what I hear, permanent blindness is a shame. Now the funny thing is that the glasses that come with this unit are the complete opposite color of my own glasses that are rated for a YAG laser like this. I don't know about you, but I feel like this could be a big problem, so I'm going to play it safe by using this stuff.

Unfortunately, I don't have any visible tattoos right now that I can burn for this video. Fortunately, this is an all-in-one device. It can also remove eyebrows, remove birthmarks, freckles and then any black dolls that are. My eyebrows could probably use a little taming, but you know what? Before I start pointing this at my face, I better try something like this piece of metal here. Alright, I've got the power maxed out, here we go, oh my gosh, that's loud, it's literally creating craters in the metal. That's a lot of damage, look at those crazy plasma fireballs, the surface must be incredibly hot.

I didn't expect this to be so strong, especially out of the box, like it's making craters in metal with nothing but light, it's crazy! This thing has great power. Right here I have a two and a half kilo piece of tungsten. Let's see what happens when I hit him with the laser. In case you don't find these impressive little craters, tungsten has a melting point of over three thousand four hundred degrees Celsius, the highest melting point of all pure metals. Now I wouldn't even be surprised if the center of the fireball was hotter than the surface of the Sun.

I know what you're thinking, what happens if you get hit by lightning? Well, one way to find out. I guess oh wow, it tickles me. I mean, yes, it hurts, but not as much as I expected. Actually, it's pretty good. Now the reason it doesn't leave craters on my skin is the fact that my skin just doesn't absorb this light very well. Now, this is especially useful for removing dark tattoos, as the laser selectively destroys dark ink without touching the skin. Kind of. As an example of this, let's say I've made the biggest mistake of my entire life and the only way for my family to love me again is to burn it.

Well, lucky for me, this is just another day at the office for this laser. Well, it was shit. I mean, yes, it erased the ink and actually did a very good job, but maybe maxing out the power wasn't the best idea. Ah, whatever my skin is. It will probably heal. Now, unfortunately, burning a tattoo is not always that simple. For one thing, my pale skin and dark ink make selectively destroying the ink much easier. But lasers are racist! I mean those with a darker complexion are much more likely to get burned because their skin absorbs more light.

And this isn't even the only complicating factor, I mean tattoos come in a wide variety of different colors, you can't use one laser for all. As an extreme example of this I have tattooed these two boards here. Now when I try to remove the one on the darker board, it's hard to keep it from destroying the surface along with the ink. but even on the lightest board I have problems. Now the dark ink comes off quite easily, but the red ink is practically untouched, so what do we do now? That's where this witchcraft comes into play.

So inside this tip is a crystal of potassium titanyl phosphate, or KTP for short. It splices two IR photons to form a green photon through a process called second harmonic generation. Now the fact that you can just screw this onto the tip to make it green is literally crazy because it's generally much harder to do non-linear optical processes like this. The green light does a much better job of removing red ink, but really. This isn't a big surprise since red and green are on opposite sides of the color wheel. Okay, it works on wood, but what about leather?

Uh, one way to find out! Oh my god, that hurts! It turns out that many things absorb green light better, and then that includes my skin! I'm so sorry guys, but I'm going to have to stop laser removing this one. I guess it's permanent now. Oh yes, isopropyl alcohol exists, right? So what else can I do with the green ray? Well, how about you clean some dirty coins? Oh, look at that like new! The polka dots give it an extra touch, don't you hate it when your transformers rust? Fortunately, with this laser you can burn off the rust right away.

Oh wow, that's amazing. I didn't even need to use corrosive chemicals, just an unimaginably

dangerous

laser. Aluminum foil reflects all but a small percentage of the light that hits it, so is it possible that we can get through it anyway? I guess so! Well, that's actually pretty crazy because remember it's just light shooting through the aluminum foil. If we watch it in slow motion, we can see little bits of burning aluminum flying off the metal, which is actually pretty cool. Oh yeah, see all those little dots in the picture? That's when I noticed them too. Oh hell.

It turns out that even without a direct hit, the laser managed to put a bunch of holes in the camera sensor and since there's no way to fix that, you might as well keep lasering until the entire sensor is blinded. This one was suggested to me by YouTube user Vidduley and is just a block of clear acrylic. Now, although it is almost transparent, it can still burn the entire beam path into the plastic. Now it's funny because I tried to use this effect to etch things in acrylic but I ended up vaporizing the surface of my table behind the block.

A balloon seems like a silly test compared to everything else, but look at this, it was surprisingly difficult, what's wrong? It turns out that the hot plasma formed on the surface ends up absorbing most of the energy of the laser pulse, which actually shields the material behind it a bit. This is why military laser weapons are almost never pulsed. When it comes to burning things with a powerful laser, it's hard to find anything easier to set on fire than a match. but this is a pulse laser, so it doesn't behave as you would expect; In fact, the laser destroys match heads without even lighting them.

I think the explosions at the surface must be too violent to allow a stable flame to form. MMM. I wonder if this laser can burn a CD? Oh yes it goes through it, even if I turn it to the shiny side it still vaporizes the metal coating. That's pretty crazy, oh yeah, I can't forget about these glasses that were sent with the kit. Surely the sellers care about our safety, right? Hey, look at that. Yes, that's right, your retinas would look like a slice of Swiss cheese if you trusted this stuff. Great help for those who bought one of these kits and used the included glasses.

Look what happens if I don't aim at anything. Oh yes, the air lights up! Think about how crazy that is. Basically transparent air explodes in the laser beam. If you want to set air on fire with nothing but light, you need gigantic energy densities. in fact, the threshold is about 300 billion

watt

s per square centimeter. That gives us a lower limit for power density, but what does that say about actual power output? The seller claims that this laser produces a maximum of 2 joules in each 10 nanosecond pulse. Now, 2 joules may not seem like a lot of energy, but when discharged in just 10 nanoseconds, we're talking about peak powers of 200

million

watts!

But let's pretend the seller is a total liar. How do we measure power output ourselves? Well, it's not as easy as just pointing it at a meter, as it turns out that most sensors simply don't like eating megawatt laser pulses. That said, we can get a pretty good estimate using just a little bit of math. Calculating the actual power from the power density means that we need to find the minimum size that the laser can focus to. Now it's hard for me to measure this directly, but we can take advantage of the fact that lasers tend to adopt a Gaussian beam profile to make some estimates. in the simplest case, you have a wave traveling along Z and polarized along X that adopts the fundamental transverse mode of the laser resonator.

Now when this happens, the time-independent electromagnetic field looks approximately like this. Now, if you're thinking "Oh wow, I'd rather gouge my eyes out than try to work with that", well, you're not alone, but it actually turns out that the special mathematical properties of the Gaussian function mean that these rays can be described. With just a few simple parameters and then manipulated with simple algebra, I started by measuring the beam divergence and then calculated the waist radius using the wavelength of the laser and this gives a diameter of about 10 microns. Now, equating a beam of this size with the minimum irradiance required to ionize air gives a minimum laser output power of one hundred and fifty thousand watts. but the thing is, there's no way for this to work even close to the perfect Gaussian beam, so if it's ten times worse with a beam diameter of one hundred microns, well, that gives a power output of fifteen million watts.

And now this seems crazy, and it's actually several times greater than the instantaneous electricity consumption of the entire city I live in, but it's actually reasonable. Okay, I have a pulse laser with a power of megawatts. Now blowing things up will always be fun, but what else can I do with it? Well, how about using it to build a laser-pumped laser? There are many ways to achieve laser initiation by using one laser to power another, but I'm feeling old school today and want to play with some chemicals too. I have an assortment of organic dyes here, some I synthesized years ago and others I purchased online.

Now, under the right conditions, these dyes can be used as a laser medium that can produce a wide variety of colors. Oh, this brings me back to my time in academia! Well, at least this does it. I'm not exactly throwing a party though, I just need to whip up some solutions of these dyes in ethanol. These dyes are extremely photoactive, so a little goes a long way. In fact, I only need about 50 milligrams per 100 milliliters of solvent and even this may be too much, so I will probably end up diluting them. Now a precise concentration is not very important, but too much dye in the solution will kill the result.

I started by filling a bucket with a rhodamine B dye solution diluted to about 10 percent of the original. Now, placing the cuvette directly in the beam path produces a colorful light, but I can't be sure if this is real laser emission. By removing the cuvette at an angle, the green laser beam is refracted throughthe cuvette so that it does not align directly with the potential dye laser beam. Now, for sure, this reveals that the liquid is actually working as its own laser, as there is now an orange beam coming out at an angle to the bomb's original green beam.

Now that's great. Since there is still a lot of green light coming out of the bucket, I increased the concentration to use more light from the pump and this actually increases the output dramatically. I found the best results using about half a millimolar of rhodamine B. Now notice that I am not using any type of external mirror to act as an optical resonator. in fact, the reflectivity of about 10% of the cuvette walls provides enough feedback to achieve an enormous amount of optical amplification. Now that's some stuff that likes to shoot! Since the reflectivity is the same on all sides of the cell, laser emission is obtained from each side of the cell, with one side typically favored more than the others.

Now the presence of the side beams that extend at 45 degrees from the main beams is interesting. Now it turns out that the corners of this square cell act as retroreflectors strong enough to form laser cavities here as well, thus forming this beautiful but terrifying instant-blind laser star. Sticking a mirror on one end causes most of the dye laser output to go in the opposite direction. , giving some kind of controllability. Still, I didn't feel comfortable seeing the output in person since the maximum power is still very high and my glasses don't even block this color. This is also a real shame because orange lasers are very difficult to get.

In terms of maximum power output, this laser tattoo removal system is actually the most powerful laser I've ever featured on this channel, so what exactly is inside this beast? I took the main unit apart to see what's inside and it's actually pretty simple. So you have some control circuitry in there, you have a water pump and a water cooling reservoir, a high voltage switching power supply and then an energy storage capacitor right here that supplies power to the pulse laser. Now notice that there are no optics here. In fact, the entire laser cavity is contained within the handle, knocking it down reveals that the laser inside is old school;

In fact, it is quite similar to the first laser ever built. Here is a flash lamp that pumps light into a neodymium-doped yttrium aluminum garnet crystal or Nd:YAG for short. This energizes the neodymium ions in the crystal and sitting between these two mirrors allows it to operate like a laser. As a side note, Nd:YAG was one of the first laser media ever discovered and is still widely used today, so it's really cool that it has survived the test of time like this. There is special optics inside the cavity that allows it to produce such absurd pulse powers. now it initially absorbs the light coming from the glass, which actually kills the output of the laser, but what it does is allow the glass to build up a lot of energy while the flash lamp fires.

But after the optic absorbs enough light, it suddenly becomes transparent, effectively exposing the highly energized crystal to the cavity mirrors. Now this causes all that energy to be discharged in an incredibly short period of time, limited by the time it takes for the light to bounce a few times through the cavity. Now this process is called q-switching and doing it passively with this little optic is probably the simplest method used. When this Q-switched laser is fired, the pulses last about 10 billionths of a second, meaning the light only travels about three meters during this time. To put this into perspective, pointing a laser pointer at the sky for one second will produce a pulse 300,000 kilometers long.

It's really hard to imagine such small time scales, but surprisingly there are already lasers that run 10 million times faster than this, so now that I've gone to the trouble of ripping it apart, is there anything I can do to make it stronger? Well, removing the Q switch would actually increase the power a bit, but that's at the cost of drastically reduced maximum power. In fact, if I want to increase the power, the best thing I can do is feed more power to the lamp. Looking at the energy storage capacitor, I see that it is rated at 1400 volts at 100 microfarads. when I actually measure the live voltage across a voltage divider, I see that it only charges to a maximum of about 800 volts, or only about 1/3 of the power it is rated for.

As a side note, using this measurement as a way to estimate maximum power actually gives a similar result to what I got before, but this time I get around 30 million watts. For fun I used this number to calculate the strength of the electromagnetic field at the waist of the beam and, as expected, it's crazy. Look at that, an electric field of more than a billion volts per meter, which is hundreds of times stronger than that produced by the accelerators at the Large Hadron Collider. This is now admittedly a small distance, but it still shows the potential of lasers in desktop particle accelerators.

Alright, let's modify this again. so I guess I have two main options here to increase production. You could increase the voltage feeding the capacitor, but since the impedance of the flash lamp is non-linear, a higher voltage would mean a shorter pulse length and that would disproportionately overpower the flash lamp. I suppose charging the cap to its maximum power would kill the lamp in one go. so I guess my other option is to add more capacitors, this will definitely increase the power but it will be done more smoothly with a longer pulse. I went ahead and added enough capacitors to triple the power in the circuit, so without further ado, let's try this. .

Alright, here we go, that was bad. Did it just break? it broke! It turns out that some underpaid graduate students in the '60s came up with these empirical equations that describe the life of a flashlamp with its driving energy. in fact, there is a dramatic ratio here, actually raised to eight and a half! That means that tripling the power of the drive for a given pulse length will destroy the lamp about 11,000 times faster than running it at its original power, so it's no wonder the lamp exploded. As a side note, almost all of the laser science in this video can be found in this book from 1976.

I learned a lot when I first read it four years ago and the information is still just as relevant today. Now, for those interested in experimenting with old-school flashlamp-pumped lasers, you'd be hard-pressed to find a better resource than this. Well, I hate to have such an anticlimactic ending, but I think I destroyed enough equipment for one video. but seriously, I destroyed the Sony camera I just bought last year and even put a few more holes in this camera I'm filming with right now, including the tattoo laser I destroyed. This was by far my most expensive video yet.

Now, luckily, I have some dedicated followers on Patreon who continued to support me even when I can't upload videos very often, so as a thank you to you guys, I'll let you watch this video first before making it public anywhere else. So yeah, thank you very much. one last thing. so even when I'm not uploading content to my channel, I usually post content to my other social networks, so be sure to check out those pages via the links in the description. I especially recommend watching my backup channel's most recent video of an incredible Thunderstorm I experienced while chasing a tornado.

Also, for all home creators and experimenters I recommend visiting my Discord server as there are a ton of knowledgeable members there and they are always working on awesome projects. So yeah, until next time, stay safe and happy!!!