Biophotonics Modalities for High-Resolution Imaging of Microcirculatory Tissue Beds Using Endogenous Contrast: A Review on Present Scenario and Prospects

Figure 6

Schematic for optical Doppler tomography. The sample arm beam is held at some angle 𝜃 to the direction of flow. Therefore, an optical signal with wave-vector 𝑘₀ falls on a particle moving with velocity 𝑢. The light scattered back into the sample objective is Doppler shifted and has wave-vector 𝑘_𝑑.