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Dangerous tattoo remover from eBay is a MILLION watt laser

Dangerous tattoo remover from eBay is a MILLION watt laser
I recently picked up this chinese-made

laser

tattoo

removal device from

ebay

now according to the specs this thing should contain a really scary pulsed

laser

system inside and if so I'd love to screw around with it when it comes to wacky eBay gadgets like this you never know what you're gonna get. for one sellers often blatantly lie about the ratings, and two this entire system cost less than having a doctor burn off a

tattoo

, so it's not like you're can expect some state of the art medical system. now that being said, I'm not super concerned with how safe or effective this thing is because honestly I just wanna blow some stuff up with a pulse

laser

. in fact, if this thing 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 fire this thing up. so uh, spoiler alert. this thing packs some serious firepower. see all those little marks in the screen? this thing is so powerful that blew a bunch of holes in my camera's sensor without even taking a direct hit. what I'm getting at is that this thing definitely isn't a toy and as tempting as it may be I do not recommend buying one of these things.

dangerous

is an understatement for this

laser

and if you don't have some high-end

laser

goggles you'll go blind using this thing. so yeah please don't try anything you see in this video at home alright so...
dangerous tattoo remover from ebay is a million watt laser
here's what all came with his unit. you got the

laser

head here and the main power supply I got these treatment specific tips that actually might be able to change the

laser

s output color. you got this really mysterious ointment, this funnel for adding cooling water, a foot switch and then these these really sketchy

laser

goggles. this manual here, if you could even call it that, turned out to be completely useless for assembling this thing, but luckily putting this thing together was really straightforward, like honestly a ten-year-old could assemble this thing, and I'm not totally sure that's a good thing. I went ahead and used deionized water for the cooling fluid as it turns out that ultra pure water is actually a really really good electrical insulator. pretty cool right? now before I power up the

laser

I need something to protect my eyeballs because from what I hear, permanent blindness is a bummer. now the hilarious thing is that the goggles that came with this unit are the complete opposite color of my own goggles that are rated for a YAG

laser

like this. I don't know about you guys but I feel like this could be a huge issue so I'm gonna play it safe by wearing these things. now unfortunately I don't have any visible

tattoo

s that I can burn off for this video luckily this is an all-in-one device. it can also remove eyebrows, remove birthmarks, freckle, and then uh whatever black doll is. my eyebrows probably could use a little bit of taming,...
dangerous tattoo remover from ebay is a million watt laser
but you know what before I start pointing this thing at my face, I better test on something like this piece of metal over here. all right I got the energy maxed out here we go oh my gosh that is loud it's literally blowing craters in the metal .that is a lot of damage check out those insane plasma fireballs the surface must be getting incredibly hot. I was not expecting this thing to be so strong especially out of the box like that's just blowing craters in the metal with nothing but light like that's insane! this thing packs some serious power. right here I have a two and a half kilo chunk of tungsten. let's see what happens when I hit it with the

laser

. in case you don't find these little craters impressive 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 't even be surprised if the center of the fireball is hotter than the surface of the Sun. I know what you're thinking, what happens if you get hit by the beam? well one way to find out I guess oh wow it kind of tickles well I mean yeah it hurts but not nearly as bad as I was expecting that's actually pretty neat. now the reason it's not leaving craters in my skin is the fact that my skin just doesn't absorb this light very well. now this is especially useful for removing dark

tattoo

s, as the

laser

selectively destroys the dark ink while leaving the skin untouched. well sort of. as an...
dangerous tattoo remover from ebay is a million watt laser
example of this, let's pretend I've made the biggest mistake of my entire life and the only way for my family to love me again is to get it burned off. well lucky for me, this is just another day at the office for this

laser

well that sucked I mean yeah it erased the ink and actually did a really good job but maybe maxing out the power wasn't the best idea here ah whatever my skin will probably heal. now unfortunately burning off a

tattoo

isn't always so simple. for one my pale skin and dark ink make selectively destroying the ink a lot easier. but the thing is

laser

s are racist! I mean those with a darker complexion are a lot more likely to receive burns because their skin absorbs more of the light. and this isn't even the only complicating factor, I mean

tattoo

s come in a huge variety of different colors you can't use just one

laser

for all of them. as an extreme example of this I've

tattoo

ed these two boards here. now when I try to remove the one on the darker board it's hard to prevent destroying the surface along with the ink. but even on the lighter board I run into issues. now the dark ink comes off pretty easily but the red ink is essentially untouched so now what do we do? that's where this witchcraft comes in. so inside this tip is a crystal of potassium titanyl phosphate, or KTP for short. it splices two IR photons together to make one green photon via a process called second harmonic generation. now the fact that you can just...
screw this on to the tip to make it green is literally insane because it's usually a lot harder to pull off nonlinear optical processes like this the green light does a much better job at removing the red ink, but really this isn't much of a surprise since red and green are on opposite sides of the color wheel. okay so it works on wood but how about skin? uh one way to find out oh oh holy heck that hurt! it turns out a lot of things absorb the green light better, and then includes my skin! so sorry guys but I'm gonna have to pass on

laser

ing this one off. I guess it's permanent now. oh yeah rubbing alcohol is a thing isn't it? so what else can I do with the green beam? well how about cleaning some dirty coins oh wow look at that good as new! the polka dots give it an added touch don't you hate it when you transformers get all rusty? luckily with this

laser

you can burn the rust right off. oh wow that's amazing I didn't even need to use corrosive chemicals just an unimaginably

dangerous

laser

. aluminum foil reflects all but just a few percent of the light that hits it, so is it possible that we can shoot through it anyway? I guess so! well that's actually pretty crazy because remember that's just light that's shooting through the foil. if we look at it in slow motion, you can see little pieces of burning aluminum flying off of the metal so that's actually pretty neat. oh yeah see all those little spots in the picture? this is...
when I noticed them too. ah heck. turns out that even without a direct hit, the

laser

still managed to blast a bunch of holes in the camera sensor and since there's no fixing that, I might as well keep

laser

ing stuff until the entire sensor goes blind. this one was suggested to me by youtube user Vidduley and it's just a block of clear acrylic. now even though it's nearly transparent it can still burn its entire beam path into the plastic. now it's funny because I tried using this effect to engrave stuff in the acrylic but I just ended up vaporizing the surface of my table behind the block. a balloon seems like a silly test compared to everything else but check this out well that was surprisingly difficult what gives? it turns out that the hot plasma formed on the surface ends up absorbing most of the

laser

pulse energy this actually protects the material behind it somewhat. this is why military

laser

weapons are almost never pulsed. when it comes to burning stuff with a powerful

laser

it's hard to find something easier to set fire to than a match. but this is a pulse

laser

so it doesn't behave like you'd expect in fact the

laser

obliterates match heads without even igniting them. I think the explosions at the surface must be too violent to allow a stable flame to form hmmm I wonder if this

laser

can burn a CD? oh yeah punches straight through it even if I flip it to the shiny side it still vaporizes the metal coating. that's pretty crazy oh...
yeah I can't forget about these goggles that were sent with the kit. surely the sellers care about our safety right? huh look at that. yeah that's right, your retinas would look like a slice of Swiss cheese if you trusted these things. big oof for those who bought one of these kits and used the included goggles. look what happens if I don't point it at anything. oh yeah the air ignites! think about just how crazy that is. air, which is basically transparent, is exploding in the

laser

beam. if you want to light the air on fire with nothing but light, you need some gigantic power densities. in fact the threshold is something like 300 billion

watt

s per square centimeter. now that gives us a lower bound on power density but what's that say about actual output power? the seller claims that this

laser

outputs a max of 2 joules in each 10 nanosecond pulse. now 2 joules may not seem like a lot of energy, but when it's dumped in just 10 nanoseconds, you're talking peak powers of 200

million

watt

s! but let's just pretend like the seller is a total liar. how do we measure the output power ourselves? well it's not as easy as just pointing it at a meter, as it turns out that most sensors just don't like eating mega

watt

class

laser

pulses very well that being said we can get a pretty good estimation using just a tiny bit of math calculating actual power from the power density means that we need to find the minimum size that the

laser

can focus down to....
now this is difficult for me to measure directly, but we can use the fact that

laser

s tend to take on a Gaussian beam profile in order to make some estimations. in the simplest case you have a wave traveling along Z and polarized along X that takes on 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 stab my eyeballs out than try working with that, well you're not alone, but actually it turns out that the special mathematical properties of the Gaussian function mean that these beams 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

laser

's wavelength' and this gives a diameter of approximately 10 microns. now equating a beam of this size to the minimum irradiance required to ionize air gives a minimum

laser

output power of a hundred and fifty thousand

watt

s. but the thing is, there's no way that this thing is operating even close to the perfect Gaussian beam, so if it's say ten times worse with a hundred micron beam diameter, well that gives an output power of fifteen

million

watt

s. and now this seems crazy, and it's actually several times higher than the instantaneous electrical power draw of the entire town that I live in, but it is actually reasonable. all right so I have...
a pulse

laser

with output the mega

watt

s. now blowing stuff up is always gonna be fun but what else can I do with it? well how about using it to build a

laser

pumped

laser

? there's a lot of ways to pull off

laser

inception by using one

laser

to drive another, but today I'm feeling old school and I also want to play with some chemicals. Here I have an assortment of organic dyes, some that i synthesized years ago and others that i bought online. now under the right conditions, these dyes can be used as a

laser

medium that can output a huge variety of colors. oh wow this brings me back to my time in academia! well this does at least. I'm not exactly throwing a party though, I just need to make some solutions of these dyes in ethanol. these dyes are extremely photoactive so a little goes a long way here. in fact I only need something like 50 milligrams per 100 milliliters of solvent and even this may be too much so I'll probably end up diluting them. now a precise concentration isn't super important but too much dye in the solution will kill the output. I started by filling a cuvette with rhodamine B dye solution diluted to about 10 percent of the original now placing the cuvette directly in the beam path does give some colorful light but I can't be sure that this is actual

laser

emission. by kicking the cuvette off at an angle the green

laser

beam is refracted through the cuvette so that it doesn't line up directly with the potential dye

laser

beam....
now sure enough this reveals that the liquid is actually operating as its own

laser

as there is now an orange beam exiting at an angle to the original pump green beam. now that is pretty cool. since there's still so much green light left exiting the cuvette i upped the concentration to utilize more of the pump light and this actually dramatically increases the output. I found the best results using about a half a millimolar of rhodamine B. now notice that I'm not using any sort of external mirrors to act as an optical resonator. in fact the roughly 10% reflectivity of the cuvette walls provides enough feedback to achieve a massive amount of optical amplification. now that's a material that likes to lase! since the reflectivity is the same on all sides of the cuvette you get

laser

emission from each side of the cell, with one face typically favored stronger than the others. now of interesting notice is the presence of the side beams running 45 degrees to the main beams. now it turns out that the corners of this square cell act as strong enough retroreflectors to form

laser

cavities here too, thus forming this beautiful but terrifying

laser

star of insta blindness sticking a mirror on one end causes the majority of the dye

laser

output to exit in the opposite direction, giving some sort of controllability. still though I wasn't comfortable viewing the output in person as the peak power is still very high and my goggles don't even block this color. this is a...
real bummer too because orange

laser

s are very hard to come by. in terms of peak output power this

laser

tattoo

removal system is actually the most powerful

laser

that I've shown on this channel, so what exactly is inside this beast? I tore down the main unit to see what's inside and it's actually pretty simple. so you have some control circuitry over there you got a water pump and water cooling reservoir a switching high voltage power supply then an energy storage capacitor right here which supplies energy to the pulse

laser

. now notice there aren't any optics in here. in fact the entire

laser

cavity is contained within the handle tearing this down reveals that the

laser

inside is old-school it's actually quite similar to the first

laser

ever built. there's a flash lamp here that pumps light into a crystal of neodymium doped yttrium aluminum garnet or Nd:YAG for short. this energizes the neodymium ions in the crystal and sitting between these two mirrors here allows it to operate as a

laser

. as a sidenote Nd:YAG was one of the first

laser

media ever discovered and it's still widely used today so it's actually pretty cool that it survived the test of time like this. there's a special optic that's inside of the cavity here which allows it to produce such absurd pulse powers. now initially it absorbs the light coming from the crystal which actually kills the

laser

output, but what this does is it allows the crystal to build up a bunch 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 get dumped in an incredibly short amount of time, limited by the time it takes for the light to make a few bounces through the cavity. now this process is called q-switching and doing it passively with this little optic is probably the simplest method in use. when this q-switched

laser

fires, pulses have a duration of about 10 billionths of a second which means that light only travels about three meters during this time. to put that in perspective, pointing a

laser

pointer in the sky for one second will produce a pulse that is 300,000 kilometers long. it's really hard to fathom timescales this tiny but amazingly there are already

laser

s that run over 10

million

times faster than this so now that I've gone through the trouble of tearing it apart is there anything I can do to make it stronger? well removing the q-switch would actually increase the energy a bit but that's at the cost of a dramatically decreased peak power. in fact if I want to increase the output my best bet is to feed more energy to the lamp. looking at the energy storage capacitor I see that it's rated for 1,400 volts at 100 microfarads. when I actually measure the live voltage through a voltage divider I see that it only gets charged to a max of about 800 volts, or only about 1/3...
of the energy that it's rated for. as a side note using this measurement as a way to estimate peak power actually gives a similar result to the one I got earlier but this time I get about 30

million

watt

s. for funsies I used this number to calculate the strength of the electromagnetic field at the beam waist and as expected it's insane. look at that, an electric field of over billion volts per meter, that's hundreds of times stronger than what the accelerators produce in the Large Hadron Collider. now granted that's over a tiny distance but it still shows the potential of

laser

s in desktop particle accelerators. all right so back to modding this thing. so I guess I have two main options here to increase the output. I could crank up the voltage feeding the capacitor, but since the impedance of the flash lamp is nonlinear, a higher voltage would mean a shorter pulse length and that would disproportionately overpower the flash lamp. my guess is that charging the cap up to its full rating would annihilate the lamp in one shot. so I guess my other option is to add more capacitors this will definitely increase the energy but will be done more gently over a longer pulse I went ahead and added enough capacitors to triple the energy in the circuit so without further ado let's test this thing out. all right here we go that was bad. did it just break? it broke! it turns out that some underpaid grad students in the 60s came up with these empirical equations that...
describe the lifetime of a flash lamp with its drive energy. in fact there's a dramatic relationship here, to the power of eight and a half actually! that means that tripling the drive energy for given pulse length will actually destroy the lamp about 11,000 times faster than running it at its original energy, so it's no wonder that the lamp exploded. as a sidenote pretty much all the

laser

science in this video can be found in this book from 1976 I learned a bunch from it when I first read it four years ago and the info is still just as relevant today. now for those out there who are interested in experimenting with old-school flashlamp pumped

laser

s you'd be hard-pressed to find a better resource than this. well I hate to have such an anti climactic ending but I think I've destroyed enough of my equipment for one video. but seriously I obliterated the Sony camera that I just bought last year and I even put a few more holes in this camera that I'm shooting with right now now including the

tattoo

laser

that I destroyed this was by far my most expensive video yet. now luckily I have some dedicated patreon supporters that kept supporting me even when I can't upload very frequently so as a thank you to you guys, imma let you guys see this video first before I make it public anywhere else. so yeah a big thank you to you guys. one last thing. so even when I'm not uploading to my channel I'm usually posting content to my other social media so be sure...
to check those pages out via the links in the description I especially recommend watching the most recent video my backup channel of an amazing lightning storm I experienced while tornado chasing plus to all the makers and home experimenters out there I highly recommend checking out my discord server as there's a ton of knowledgeable members there and they're always working on awesome projects. so yeah until the next time stay safe and happy lasing!!!