In 1958, Schawlow and Townes, working with
microwaves, first proposed a technique for the
generation of monochromatic radiation by
stimulated emission. They produced
monochromatic radiation in the infrared optical
region of the electromagnetic spectrum with an
alkali vapor used as the active medium.
Maiman, using a ruby crystal in 1960, developed
stimulated emission of a red-light beam with a
wavelength of 694 nm. This was the first
working laser, and it is from this prototype
that today's lasers are derived. Since 1960,
research and technical advances have adapted
lasers to dermatology. Leon Goldman, the
father of dermatologic laser surgery, published
preliminary results on the effects of a ruby laser
on skin diseases. Early work with the ruby laser
consisted of ablation techniques. Little bleeding
was noted after nonspecific damage to the
superficial dermal layers , and small areas o f
skin could be treated with high-intensity
radiation with few sequelae.
Not surprisingly, the ruby laser was found to
treat pigmented lesions well owing to its
ability to target melanin. Today, there are
numerous lasers that can specifically target
pigmented lesions, including other red light
lasers (ie, alexandrite, neodymium:yttriumaluminum-garnet
[Nd:YAGI) and green light
lasers (ie, 510-nm pulsed dye, 532-nm frequency-doubled
Nd:YAG). The wide range of