This paper aimed to summarize available facts about the spectral influence on reflection, refraction and absorption and to measure relative absorption of different wavelengths. The experiment showed that longer wavelengths lead to decreasing energy absorption and refraction index in the melanin, as well as a reduction of hemoglobin energy absorption. Longer wavelengths increase the probability of the interaction with water particles and its own light absorption. We conclude that reflection and melanin absorption are negligible for wavelengths higher than 1000 nm due to the ability to penetrate higher amounts of energy into the tissue. Additionally, water absorption increases with the longer wavelengths and refraction index and hemoglobin absorption are reduced.
Marshall RP and Vlková K