ABSTRACT
The Q-switched alexandrite laser, used for the treatment of pigmented lesions and tattoos, is a solid state laser, which emits light at 755 nm with pulse durations between 50 and 100 nsec. There are fewer published data about this laser as compared to the Q-switched ruby laser. However, because the wavelength and pulse durations are similar to those of the Q-switched ruby laser, the results are similar. A good response has been seen in the treatment of lentignes and cafe au lait macules. Dermal pigmented lesions, such as nevus of Ota, also respond. The 755 nm wavelength of this laser penetrates deeply enough to affect the growth centers of hair. In fact, the longer the wavelength is, the deeper the penetration. Thus, alexandrite laser wavelengths although not as well absorbed by melanin as compared to the ruby wavelength, do penetrate more deeply into the dermis (Figures 2.1, 2.2). Nevertheless, as with the Q-switched ruby lasers, there are no documented cases of long term hair removal induced by Q-switched alexandrite lasers.
