What factors determine the depth of laser light penetration into tissue?

The depth of laser light penetration into tissue is primarily influenced by the wavelength and tissue composition.

Wavelength is a crucial factor because different wavelengths of light are absorbed by tissues at varying rates. For instance, certain wavelengths may be absorbed by pigments in the skin or other biological materials, while others may penetrate deeper without significant absorption. This means that a laser with a specific wavelength might be more effective for targeting particular tissues or structures within the body.

Tissue composition also plays a significant role because different types of tissues (such as muscle, fat, or bone) have distinct physical and biochemical properties, which affect how they absorb and scatter light. For example, some tissues are more transparent to certain wavelengths, allowing deeper penetration, while others may reflect or absorb more light, limiting the depth of penetration.

Together, these two factors—wavelength and tissue composition—determine how well the laser light can penetrate the tissue and reach the intended target, making them the most influential considerations in the context of laser applications in medical settings.