I have noticed that laser epilators as well as IPL’s do not focus the beam. They all work in a mode where they cover an area that is large compared to the follicle size. Skin receives the same fluence (energy/unit area) as hairs. Being an electrical engineer at government lab with laser all around me, I wonder why no one has developed a laser hair removal system that focuses the beam to the hair diameter. Hairs would be zapped one by one as with electrolysis which would be more tedious but there would be a lot less exposure to the skin. Such a system would put all of the energy where you want it: into the hair and follicle. I think you would shave the area to be treated and then zap the top of each hair at the skin surface. You would also need an integrated magnifier with a visible pointing laser to aim it. I think dentists have lasers somewhat like this.
Laser doesn’t “see” the skin. The pigment in the hair attracts the heat. Skin doesn’t have that pigment. That’s why hair needs to be dark AND coarse. It has the most pigment and can absorb the most heat, which in turn disables the follicle.
What you’re describing is basically electrolysis. Laser was created to make the process faster.
LAgirl,
Thanks for the reply. I think you will find that all skin does abosrb some fraction of the laser powere at wavelengths typically used in hair removal which are typically in the near ifrared. I promise that if you stick you hand in a CW beam operating at any of the wavelengths used, it will burn your hand. Light skin absorbs less than dark skin and (it seems) that dark hair abosrbs more than light skin so some of the energy goes where you want it (into the hair). What I am suggesting is not electrolysis because it does not involved inserting needles into the skin but as I posted, it would require targeting each hair by itself. I have a sense that if ever developed, it would have a higher “kill rate” than the broad area schemes now in use. Since laser does seems to have an effectivness issue and a discomfort issue, I am just putting the idea out there to see if anyone know if this has been tried. Its just an idea: maybe a good one and maybe not.
I think that’s what the Sciton lasers are supposed to do when they scan the area first then fire at each hair… http://www.sciton.com/products/clearscan-alx.html
To Rodsinger: Well, it was tried! During the 1980s a physicist in Illinois had a focused laser — exactly as you explain. During a 10 year period, different goups of electrologists (including Hinkel himself) visited the guy. I do not remember his name and have no idea what became of his experiment. But YES, it was a focused beam of coherent light about the spot size of a follicle.
He also tried a very fine fiber optic to literally place the laser in the follicle itself. I remember he was experimenting with the fiber optic because once the hair was shaved you couldn’t find it. (He had to shave the hair so that the laser didn’t just burn off the hair above skin level.) I’m going to do some digging to find out the guy’s name.
>edokid
I looked up the Sciton gizmo. It is a scanning laser but I don’r think it targets the follicle. It scans to fill in the treatment area.
>Michael
I’ll be very interested to see anything you can find. I like the fiber idea but I see two problems. First is that since galss fiber is brittle it could break off under the skin which would of course be bad. There are plastic fibers but I don’t know if they can handle enough energy to kill a hair. Glass fibers might have the same issue: may not handle the energy without internal optical damage. I figured that if you shave the area and then look with some magnification, you could see the top of the hair. I suppose you could design a special trimmer that leaves a few mil of hair sticking up. The setup I have in mind would integrate a camera with the laser and a cross-hair graticule for aiming. The camera/laser would be movable with motors. You’d aim at hair on the monitor and zap it.
Well, what you’re proposing is basically electrolysis, but without insertion. I would assume that the process would be too slow and wouldn’t be worth the investment to compete with current methods.
LAgirl: yes you are totally correct. I remember Hinkel telling me that the “electrolysis-type laser” would be interesting, but “what’s the point, it’s still hair by hair.” Hinkel said laser would get interesting when they can treat a large area all at the same time! whadyknowaboutDAT!
Isn’t it odd that electrolysis, that IS invasive, is not “medical,” but laser, that is NOT invasive, is “medical?” (Like inserting a needle all the way to the sub-dermis and performing electro-surgery is NOT medical?" I hate to say it, but “Madonna Mia!” I would even add: “Pizzaria!”
Damn government bureaucrats!