Where does laser light go?
Choose a wavelength. Watch how far the light travels before it is absorbed.
Same model tissue and drawing scale for all three wavelengths.
Moving dot: lightBend: scatteringAmber glow: absorption
Illustrative paths in water-rich tissue containing blood and pigment, not measured penetration depths. Absorption deposits energy; scattering changes direction. Infrared light is invisible and is shown in false colour. Surface reflection is omitted to keep the comparison simple.