Interaction between Laser Radiation and Biological Tissue

The interaction between electromagnetic radiation and biological tissue depends on
The wavelength of light, which determines the energy of each photon of light..
The intensity of radiation.
The shape of irradiation (continuous or pulsed).
For power levels are up to few Watts, the interaction is divided into 3 regions of wavelengths
Short UV region - the photons interact with the proteins, RNA and DNA, and usually kills the biological cells.
Near UV and Short visible range - photochemical reactions such as photosynthesis. Especially with the Excimer laser.
Visible and Near Infra-Red region - Thermal effects due to absorption of the radiation.