Abstract
The medical application of femtosecond lasers has certain disadvantage such as a photochemical damage to living tissue caused by multiphoton absorption, which should be addressed. In this study, changes in the UV absorbance of amino acid by femtosecond laser irradiation are investigated. Histidine, which is an essential amino acid, is selected as the sample. The results indicate that a change in UV absorption is observed around 270 nm. The amount of change depends on the peak intensity of the laser, suggesting that the structure of histidine is influenced by multiphoton absorption during the femtosecond laser irradiation.
