Lasers and how do they work?
Many patients are interested in laser treatments for skin rejuvenation, treatment of brown spots, treatment of acne, treatment of blood vessels, and scars among other concerns. There are many lasers from many manufacturers of different wavelengths but what does all this mean?
First off, what is a laser? A laser is a device that emits light at a specific wavelength. This means that it may emit visible wavelengths such as red or green or it may emit wavelengths in the infrared spectrum (longer wavelengths than visible light). Why is this important and why do we care? In the skin there are targets that the laser is trying to destroy. For instance, if someone has a lentigo (brown spot) that he or she does not like, we could target it with a laser wavelength that is absorbed by the brown pigment cells but not by other cells. As the laser light is absorbed it heats the target and destroys it. This allows lasers to be precise. Some lasers target water. Since most of our skin is made up of water, these lasers are typically used to treat the top layer of skin in a controlled manner to allow for rejuvenation (resurfacing lasers).
Red blood cells in vessels absorb light in the visible spectrum (typically near green). By using a laser such as PDL at 585nm or KTP at 532nm, the red blood cells selectively absorb the laser heat and destroy the vessel. Similarly, lasers that target melanin (responsible for brown spots) heat up the melanin and destroys pigment. This is also how hair removal lasers work. They target the pigment cells of the hair. This is the reason you may be told that gray hair or blonde hair will not be able to be removed with a laser.
A unique category is the IPL “laser” used commonly. In actuality, it is not a laser but rather emits a range of wavelengths. It is for this reason that it can be used for brown and red spots but is slightly less specific than lasers that target specific wavelengths.
So this is a small snapshot of laser physics. There are many other parameters that have to be accounted for to properly operate a laser but I hope that this will allow you to ask questions and understand why a certain laser will be helpful for your unique skin type. It is also the reason that it is important that laser operators understand all the fundamentals of lasers and how they work.
If you have any questions about lasers or laser treatments, please contact us at Lucent Dermatology and Skin Surgery Center Specialists and we will be more than happy to explain this further. We also offer a wide range of lasers and are happy to discuss them with you as well!