Figure 1
From: Study of probe-sample distance for biomedical spectra measurement
Diagram of the possible return paths of light from tissue in a single fiber probe (a) and multi-fiber probe (b). r: radius of the fiber core, d: distance from the probe to the tissue surface. R sp : Specular reflectance, R air : Reflected signal to air (signal loss), R core : Collected signal that can transmit in the fiber, R cladding : Signal to the fiber cladding (signal loss), q: Acceptance angle of fiber. r c : Size of fiber cladding, β: probe tilt angle.