Laser Types

Resurfacing Lasers: For facial lines, wrinkles, scars, and laxity. These lasers emit light that is well absorbed by the water in skin.
CO2 (Ultrapulse) Melts or vaporizes the outer layers of skin using light in the infrared and microwave range of the spectrum. Requires the longest downtime, but as new cells form, a smoother and tighter skin surface appears.
Erbium:YAG (Derma-K) Uses mid-infrared light but with less heat than CO2 so recovery time is shorter. YAG refers to the lasing medium, a yttrium-aluminum-garnet crystal rod containing atoms of erbium, a rare-earth metal.
Fractional (Fraxel) One of the newer and sexier lasers, approved by the FDA in March 2005. It emits a very thin beam of infrared light that creates thousands of microscopic wounds surrounded by healthy tissue, resulting in more rapid healing. Usually far less painful than CO2.

Vascular Lasers: For blood vessels, spider veins, and port-wine stains These lasers emit light that is well absorbed by hemoglobin, thereby reducing redness while leaving surrounding skin relatively undamaged.
KTP (VersaPulse) Emits green light in the visible range of the spectrum.
Nd:YAG (Cool Touch) Another type of YAG laser, emitting light in the infrared range of the spectrum using the element neodymium.
Pulsed Dye (V-beam) Emits yellow light in the visible range of the spectrum.

Pigmentation Lasers: For dark spots, freckles, and sun damage These lasers emit light that is well absorbed by melanin, making them effective at reducing brown pigmentation.
Alexandrite (Apogee) Emits red light just at the limit of visibility.
Ruby (EpiPulse) The first laser, invented in 1960. Emits red light in the visible range. Doesn't use a ruby but an aluminum-oxide chromium crystal, which is ruby red.

Tattoo-Removal Lasers
Alexandrite For black, blue, and green pigments.
Nd:YAG For black, orange, and red pigments.
Ruby For black, blue, and green pigments.

Hair-Removal Lasers These lasers work by destroying the hair follicle. Usually requires a series of treatments as hair doesn't grow uniformly.
Diode (LightSheer) Uses a semiconductor--a solid material such as silicon that has electrical conductivity--to produce a laser beam that emits near-infrared light.
Nd:YAG Safer for darker skin.