The principle for blood vessels treatment lies in selective photothermolysis theory. The major targeted chromophore in facial vascular treatment is oxyhemoglobin that existing in red blood cell in vessels. Chromophore is the essential substance that absorbs laser energy. Appropriate pulse width and energy will be set in accordance with different thermal relaxation time. Then vessels will be damaged without hurting surrounding tissues.
According to the curve of absorption by targeted substance, oxyhemoglobin shows a much higher absorption interval in 900nm-1000nm. Thus 980nm semi-conductor has the ideal treatment effects for facial vascular removal.