What does the absorption of light by tissue primarily depend on?

The absorption of light by tissue is primarily determined by the tissue type and the wavelength of the light. Different tissues in the body have varying compositions and structures that influence how they absorb light at specific wavelengths. For instance, melanin-rich tissues will absorb certain wavelengths of light more effectively than lighter tissues, such as those with a higher concentration of water. Additionally, specific wavelengths correspond to different absorption peaks for chromophores—substances that absorb light—found in various tissues.

Understanding this relationship is crucial in laser applications, as selecting the appropriate wavelength based on tissue absorption characteristics can enhance the effectiveness of treatments, such as minimizing damage to surrounding tissues while targeting specific structures. This understanding underpins many laser therapies, highlighting the importance of both the type of tissue and the wavelength used when assessing light absorption.