How deep into the tissue can laser light penetrate?
The level of tissue penetration by the laser beam depends on its optical characteristics, as well as on the concentration and depth of the chromophores, which according to the wavelength are absorbed at different percentages. For instance, water absorbs almost 100 percent of the laser irradiation at the 10,600 nanometer wavelength, the wavelength of the CO2 gas laser. That is the reason why this type of laser wavelength is used in surgical applications. Other factors affecting the depth of penetration are the technical design of the laser device and the treatment technique used. There is no exact limit with respect to the penetration of the light. The laser light gets weaker the further from the surface it penetrates with a limit at which the light intensity is so low that no biological effect of the light can be measured. In addition to the factors mentioned above, the depth of penetration is also contingent on tissue type, pigmentation and foreign substances on the skin surface. Bone
