Fig. 1. Diagram of photon movement in tissue

Fig. 2. Diagram of photon movement near fiber

Fig. 3. Different situations of photon's translation near boundary of sphere. (a) Photon does not strike boundary; (b) photon strikes boundary

Fig. 4. Absorption of tissue at r=0.03 mm for finite width beam in longitudinal direction. (a) Gaussian beam at positive z direction; (b) flat beam at positive z direction; (c) Gaussian beam at negative z direction; (d) flat beam at negative z direction

Fig. 5. Absorption of tissue for finite width beam in radial direction. (a) Gaussian beam at z=0.04 cm; (b) flat beam at z=0.04 cm; (c) Gaussian beam at z=-0.04 cm; (d) flat beam at z=-0.04 cm