I recently bought some green laser pointers on eBay and somehow they ended
up even worse than my already low expectations so I'm going to tear these
things apart and see what I can do to make them stronger. now before I start
tearing these things apart I want to show you guys exactly why these things
are such garbage. for one the seller must not have tested them before shipping
because half of them don't work in the slightest bit
and the ones that do work are incredibly dim. perhaps the biggest issues that these
things can't even light things on fire like in this day and age my laser pointer
should be able to incinerate the things it is pointed at and honestly
anything less than that is quite embarrassing
now before I go on I should probably say that the crazy stuff that you're about
to see was done completely for educational purposes and in fact if you
were to try any of this stuff at home you'd probably die so please don't try
this at home without further ado let's tear this thing open but first I have
to set up my makeshift laser lab
you're probably wondering why I just plugged myself into the outlet well that's
because I'm keeping myself and my work area grounded to keep any static from
building up as this could fry the sensitive electronics I'm about to break into
don't worry there's a resistor there between me and ground to prevent myself
from becoming a light bulb if I were to touch something hot don't try this at
home kids! these laser pointers are typically press-fit together and usually
come apart fairly easily with a vise now here I've pulled out the laser module and
exposed the driver now notice there's actually a small part on the board that
looks kind of like a screw now this thing is actually a potentiometer and it
controls the amount of current going into the pump laser diode now hopefully
turning it will give us more power let's see if this little mod is gonna work
first I better put on my laser goggles that way I'm not instantly blinded all
right here we go yeah there's that pathetic output well let's see what
happens here. oh wow it's it's definitely brighter let's see if it can burn
anything. ha it barely stings at all! this thing has a long way to go before
I'm satisfied. even with the potentiometer cranked all the way up it
still just isn't making enough power so it looks like I'm gonna need to make my
own power supply. I went ahead and removed this crappy little driver.
now I have the pump diode hooked directly up to my variable power supply. if it
proves to be tough I can build my own driver for that can handle high power
all right let's see what this thing is capable of okay there's a little bit of
output all right now we're getting somewhere that's a lot brighter although
still I think could be a little bit better than this yeah it definitely
needs to be stronger let's keep cranking it up wait is that
it is it dead already?
well if it wasn't dead earlier it definitely is now here I've torn down
the laser cavity to show the internal optics now truth be told this thing was
doomed to fail from the beginning well that being said the technology inside of
a green laser pointer is actually really interesting so it starts by taking light
from this infrared laser diode and feeds it into this neodymium doped yttrium
ortho vanadate crystal and that converts the light into an even deeper infrared
then that is shone into this harmonic crystal over here which doubles the
frequency into green light. now this technology can definitely be scaled up
to higher powers but if I want say the brightest laser pointer in all of
existence then I won't be able to jam the necessary crystals and optics into a
laser pointer so I'm going to need something different. right here I have
the nicha NDG7475 green laser diode which is actually the brightest laser
diode out there that can still be jammed inside of a laser pointer. now this is
the future right here. now just to give you an idea on how fast laser tech has
evolved recently this is the kind of setup that you need to match the output power
of this little diode just five years ago. running this thing bare would kill it in
seconds from the waste heat that it produces so I pressed it into a heatsink by
making this tasty laser diode sandwich. next I soldered it to this tiny buck
driver in order to provide current regulation. now the laser diode itself is
rated for a max of 1.8 amps of current but I decided to push my luck a bit and feed
it 2.3 amps. now this should give me about 1.4 watts of output power which is
downright terrifying for a laser pointer. I'm gonna make sure I haven't killed it
by testing it on this power supply. oh yeah that's what I'm talking about. on
the final product I'll use a lens to converge all that output into a tight
beam. now building a laser pointer of this size is actually pretty tricky. in
fact all my first attempts at building a pen laser were complete failures but now
I've done it a bunch of times so I have a pretty good feel for what's going
on. now that being said this laser pointer is gonna present some additional
challenges the biggest is this puny little switchboard here. like if I were
to use this switch to try firing up that giant laser diode like it would just
destroy this thing. like that's the equivalent of using my pulsed laser
power supply to power up a light bulb
it's not like I can just jam a bigger switch in here. there simply isn't the
space for it but luckily this is where the MOSFET comes in. this little MOSFET
can switch up to 620 amps of current. what a time to be alive right? now I'll
use this thing to handle the brunt of the power switching then use this
puny little stock switch to signal to the MOSFET when to turn on. I stripped
all the components off of the switchboard and then added my MOSFET as well some
resistors now actually jamming all this stuff inside the laser pointer turned
out to be really difficult in fact I spent more time doing this than
everything else combined. and lo and behold here is the completed laser
pointer. now I'm using a glass lens and a threaded mount to make it easier to
burn stuff. but there's still one last issue though. the original laser pointer
took two triple-a batteries and now considering the new laser circuitry
draws about 20 watts these teeny little triple As aren't going to cut it but
luckily the chemical engineers have come up with some awesome lithium-ion
batteries like this little 10 440 here now it's the same size as the triple-a
but it's capable of many times higher peak output power all right here we go. why do I
even build this kind of stuff? wait what? oh yeah wrong laser pointer let's
give that another go. oh yeah that's what I'm talking about. now that's a laser
pointer I'm not ashamed to use. I don't think I can convey just how insane this device is
like just the very idea of a laser pointer having so much power
that it exceeds the highest laser danger ratings in the United States just flat out
stupid. like there's no reason anything that should ever be made and yet here I
am with a class 4 laser jammed inside of a laser pointer housing. now before I start
incinerating stuff I want to show you guys some cool fluorescence tricks like
check out that really cool color change when they hit those fluorescent
airzookas as well as that mailing sticker over there. but also I have this
vial here of 2,7-dichlorofluorescein and it glows a really nice orange
wow you can hear a boiling when it hits it that's crazy
now it's time for the best part of the video as I'm about to burn a bunch of
stuff with the laser. now if you skipped ahead to this point just because you
want to see some stuff get blown up well you've come to the right spot.
now just to put some numbers behind how bright this thing actually is a typical
one milliwatt laser pointer has a luminous flux of a little under a tenth
of a lumen. the green laser pointer comes in at about three lumens and now my new laser
pointer right here as luminous flux about 800 lumens which probably makes it
the brightest laser pointer in the entire world
of course the brightest laser pointer in the entire world is gonna depend on what
your definition of a laser pointer is. now for lasers that fit inside of a to
triple-a host this one is likely to be the brightest. now of course this comes
at the expense of a pathetically low duty cycle and as well as an incredibly
short battery life. that's all I have for you today but before I go I want to
give a big thank you to my patrons on patreon for making videos like this
possible. as a thank you for all your generous support I'm gonna let you guys see
this video first before I make it public anywhere else and yeah until the next
time stay safe and happy lazing! what are your thoughts on this circuit puddyton?