What are pulsed dye lasers?

The most common pulsed dye lasers use a flashlamp to energize the laser. The active medium is a fluorescent dye, often rhodamine. This will generate a wavelength between 200 and 700 nm. The older vascular lesion pulsed dye lasers used either 577 nm or 585 nm as the preferred wavelength, corresponding to a small peak in the oxyhemoglobin absorption spectrum in an area that does not have much competition from melanin. Newer pulsed dye lasers offer wavelengths that range from 585 to 600 nm. The flashlamp generates pulses with a duration of 300 to 500 msec in older lasers and up to 40 msec in newer lasers.