Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

Laser Hair Removal






blu-ray will not cause cancer, period. it doesnt matter what wavelength/color you use for damaging yourrself, once its above 3xx nm. i dont remember where radiation begins to have other effects than just thermal, but its deep in the threehundrets. 380nm and above will only have thermal effects. so you will burn your skin or eyes the same, no matter if 380nm, 650nm or 1064nm. what would change is reflectance/absorbance, at some point more and more light gets reflected off your skin (405nm burns your skin better than red), and eventually wouldnt penetrate your eye all the way down to your retina (so you wont burn your retina with that 10600nm co2, "just" your cornea).
i would think this is one of the more basic things to know about lasers, just like "can i put a green filter in front of my red laser" and "can i focus my LED/lightbulb to a laser?" and the like.

about topic, laser-hairremoval.
i read quite a bit about that stuff, having considered to build such a hair-remover.
there are a) invalid devices being sold, b) valid laser-powered ones being sold and used in clinics, c) and non-laser ones being used in clinics.

a) costs around 1-200$, is 808nm, and 0.5 to 1 watt. it shines a collimated beam on your skin as long as you push the switch. around one cm². this is way too little thermal energy to be effective. most people reviewing it are totally unhappy seeing no results at all, with a few being somewhat happy, with little effects when repeated often. by often i talk about dozens, hundreds of times over months. i say cheap, useless, and really dangerous, as it has no safetyfeatures at all. shine around your room, look into it, nothing prevents that.

c) these are really bright "conventional" lightsources, like flashtubes, with filters to pass the effective wavelengths. not practically doable at home, or much more expensive and difficult that with a laser. read on wikipedia for more about those..

b) yes, they exist. the only one i found is around 1000$ with 40 watts of 808nm. after having planned to build one myself, i cant really believe they sell it that cheap, the laserdiode-bar alone is more expensive when new and in small numbers. anyway.
first, you need high power, no matter what. these 1000$ things focus on a 1cm² area too. from what i read, they are really effective, having only the regular limits that were hinted here too, the hairgrow-phases. you can only kill and (somewhat) permanently remove hair which is in its growing phase. if its in its wrong phase, you can throw as much energy at it as you like, it will just burn your skin. any optical system has this limitation. with such a professional (40w) system you can remove much of the hair permanently in a few sesions. more-or-less guessed numbers: 4 sessions, once a week, could remove 75% of the hair, with 25% growing normally, and additional 25% coming back "spontaneously" over the next several months.
these systems vary outputpower and pulsewith. a normal treatment would be a single pulse of 30w for 0.2 seconds, on a 1cm² area, for example. depending on your pain-treshold and what hairtype it is. only one "shot", then next spot.
talking about hair and skin: the lower the wavelength (red), the better it gets absorbed by both the hair and the skin. 808nm seems good, being absorbed well by the hair (melanine), wild guessed 80%. the skin absorbs so-so, meaning its no big problem with white skin. forget it with non-caucasian skin, and even then you shouldnt have *any* suntan. if you have darker skin, for whatever reason (which in every case means your skin has more melanine in it, yes, same as the hair), you can use a higher wavelength. 1064 comes to mind. that could (again, guessed numbers) be absorbed by the hair only by 40%, but would be much easier on your skin, obviously better than just using a lower-powered 808nm one, since the pros use 1064nm in that case.
enough theory, lets diy!
a) get a fibercoupled high-power 808nm laser. 40w out of a fiber will cost you 500 to 1000$, used. this is the most expensive and by far the best option. get a *huge* heatsink with fan.
b) the bars are much less expensive. available up to 100w. i dont think its possible to fiber-couple those 19 emmiters in those 1cm bars at home. i cant come up with a device that uses a bar for a hairremover, just too bulky and impractical.
c) use a "low-powered" single diode. that would be 5w or absolutely maximum 10w, when pulsed and cooled and all. it shoule be doable to fiber-couple it. with 10w, you should have somewhat acceptable results with higher pulselength and perhaps smaller area too.
d) do that, with many diodes. get like 10, 20 individual diodes, couple them into a fibre individually, bundle the fibers. for most uses such a bundle would be useless, but here its fine. you can collimate any light to a spot as small as its surface (only). with our use, a spot of 1 cm² or larger is what we need anyway. with a 0.2mm fiber, and 16 fibers (cylindrically arranged) you would have a bundle-diameter of only 1mm! more? you can fit a lot of fibers on a cm² ;-)

so, if you definitely need a laser-hair-remover, on a budget:
get laserdiodes or laserdiode-chips from heerursciences, fibers, heatsinks, electronics and googles. bring a stereo microscope. and much time. eventually, you may end up with a seriously strong and useable laserhairremover.

i watched ebay the last months, and a few times tried to buy a 20w+ fiberarray for 150€ max, but was overbidden every time. some weeks ago someone wasnt sure about permanent bodymodifications any more, which ended my plans.
some ideas on the way:
-couple a greenie into one of the fibers for aiming
-full control of pulsewidh and power and focus
-integrated watercooled sapphire-window for skin-cooling and higher energydensity

well, as you can see, i spent my share of time on this topic. i can go into (even) more detail if asked, and can come up with real numbers from large-scale studies too.

at the same time i am glad and sorry to not build that monster. it would have cost me so much time which i dont have, but would be some good step forward in learning and building.. :-)

manuel
 
oh, one more thing: its about powerdensity, just like "regular" burning. take 5x5mm instead 10x10mm, and you just need a quarter of the energy. for a real simple and dangerous and ghetto laser-hair-remover: take your average x00mw red pointer, focus it, and see how much you can stand! :-)
seriously: you may get away with that when only removing individual hairs. obviously you have little control on either "pulsewith" and area. you will probably burn your skin eventually, which should be temporary. but, pretty please: protective googles! and stay away from moles, even if they have those nasty hairs coming out :-P
you can see the wavelength-effect easily: blu-ray burns your pale skin much more than red, and 808/1064 will be even better.

manuel
 
808/1064 will better what? burn? The idea here is NOT to burn your skin, and only the darker hair follicles. It ONLY WORKS with pulsed laser. YAG is the most common. That's why shrecken licht is the only one here that cannot grow a mustache. :whistle:
 
lasersbee said:
ROFL.... I thought that Video was real at the start...
Jerry
Click to expand...

Got me too... looked very convincing until i noticed the onoin ;)


As for removing hair: the lasers normally used are on the IR border. This is not so because of any cancer risk, but because such wavelenghts are absorbed by pigments in the hair, but not much by the (caucasian) skin. Usable lasers would be either 808 pumps or 780 cd writer diodes.

Building one yourself is something else... who knows how many w/cm2 to use, and how long the pulses should last - let alone tailoring that to the subject. If you could get exact specs, it could be doable, but without, i think it will end up dangerous, ineffective, or likely both.
 
Krutz said:
blu-ray will not cause cancer, period. it doesnt matter what wavelength/color you use for damaging yourrself, once its above 3xx nm. i dont remember where radiation begins to have other effects than just thermal, but its deep in the threehundrets. 380nm and above will only have thermal effects.
Click to expand...
That is NOT correct. I think what you're thinking of is ionising radiation, that indeed begins at about 315nm (for Francium and Cesium, which aren't really significant in biological terms). Chemical reactions - including damaging ones - can be caused by visible and near-IR light as well. After all, that's why you can see.
 
i agree. i have ionising radiation in mind, simply because "cancer-uv" wavelength is pretty close to the ionizing "boarder". be it some tens of nm above or beyond doesnt really matter to me. uv covers 400 down to 100 nm, compared to how many colors we name between 400 and 700nm thats a pretty wide range.
about photochemical/photobiological reactions: i dont know *any* which will cause damage earlier than the correspondent thermal damage. in fact i only know the "seeing-reaction" you mentioned, with some molecules being split by light. and even here: you wont be damaged by that at any point. even with all those transmitters split, its only temporary until new transmitters are combined/produced. if you didnt damage your eye by "hard uv" or thermal damage, it will be fine only minutes later.
i am no biologist, perhaps i`m wrong. and hey, do you know that laser-comb for growing hair? or laser-accupuncture? :-)

how about a new topic on uv, hard-uv, ionizing, blu-ray and so on? this here was about hairremoval, which shouldnt be done with anything near violet anyway ;-)

manuel
 
LOL blame Jander. I was thinking IR personally. But I have 0 education in wavelengths, ionizing, ect. I just wanted to know if it was possible.
 
possible, with either much money and reasonably much time, or much time and reasonably much money, as always ;-)
for one "use" alone it may not be worth it. you could almost buy professional treatment for this money. but then, you would have a multiwatt-array of 808nm pumping power at the end too ;-)
if lasers and diy isnt a hobby.. dont try it, too expensive in either way ;-)

manuel
 
Methods. Fifty volunteers, primarily Fitzpatrick skin types II and III, with dark brown or black hair, were treated with a diode laser (800 nm, 10–40 J/cm2, 5–30 msec, 9 mm 9 mm, 5°C chilled handpiece). Each subject had eight treatment sites at varying fluences and pulse durations, as well as a varying number of treatments and pulses. Hair counts were obtained at each site at baseline, 1, 3, 6, 9, and an average of 20 months after treatment.

Results. After one treatment, hair regrowths ranged from 22 to 31% at the 1-month follow-up visit, then remained stable between 65 and 75% from the 3-month to the averaged 20-month follow-up. After two treatments there were relatively longer growth delays, with hair regrowths plateauing beginning at 6 months after treatment and ranging from 47 to 66% for the remainder of the follow-up evaluations. Side effects were limited to pigmentary changes, transient in subjects with skin types II and III.
Conclusions. This 800 nm diode laser with a chilled sapphire tip and variable pulse duration is safe and effective for long-term hair reduction in individuals with skin types II and III.


from:
lou et al 2000 - hair reduction by diode laser 800nm
it took quite some tim to find real numbers..
combine this with the knowing good home-laserhairremoval with 40 watts, and you get the idea..

manuel
 
Sorry to fret fellas I just was posting on my tag removal program w/over 200mW

of 405nm... I have in the past had them SCRAPPED off by the doctor just to get them to come back...

In lite of this thread went I owe Tech an appology sheez... It did hurt though and I was desperate... Keeped shaving the damn thing:eek:...

One more thing they haven't come back yet no scar and smooth...:lasergun:
 
Last edited:
whats a "tag"? couldnt find anything in google nor dict.. whatever it is, glad its gone ;-)

manuel
 
Well you said that above 380nm nothing but thermal damage occurs, but sunburns aren't thermal damage.What wavelength is the UV that gives you suntans? :/
 
Jander no big deal...dont take it personaly. Education is education so harm in any of it. Dont sweat it.

Skin tag= skin tag is a common, acquired benign skin growth that looks like a small piece of hanging skin. Skin tags are often described as bits of skin- or flesh-colored tissue that projects from the surrounding skin from a small, narrow stalk. They typically occur in characteristic locations including the neck, underarms, eyelids, and under the breasts (especially where underwire bras rub directly beneath the breasts). Although skin tags may vary somewhat in appearance, they are usually smooth or slightly wrinkled and irregular, flesh-colored or slightly more brown, and hang from the skin by a small stalk. Early or beginning skin tags may be as small as a flattened pinpoint-sized bump around the neck. Some skin tags may be as large as a big grape.

Skin_T2.jpg
 
wikipedia tells UV as being between 1nm(!) and 380nm(!).
under 200nm it is ionizing. which is why it doesnt occur on earth, the sun`s <200nm uv ionizes the oxygen and is thus absorbed before reaching the ground.
254nm is what is used to desinfect (destroying dna) technically.

but, wth, no definite answer about what wavelength is the boarder to do more than thermal damage..
UV-A (320-400nm) does damage already. "shorttime"-tan, melanome-danger etc.


thanks for the "tag"-info. never heard of these. is it pure friction-caused irritation, which would go by itself again?

manuel
 
You must log in or register to reply here.





Back
Top