Backscattered signal in OCT is described as light that returns toward which component?

• A. Toward the light source
• B. Toward the detector
• C. Lateral across the tissue
• D. Absorbed by tissue

Answer: (B)

The light that forms the OCT signal is the portion that returns back toward the detection path. After entering tissue, photons scatter in many directions, but only the ones that travel back along the optical axis toward the detection optics (and ultimately the detector) can interfere with light from the reference arm to produce the depth-resolved signal. Light moving toward the source or sideways through tissue does not reach the detector to create the OCT signal, and absorbed light is removed from the detectable signal. So backscattered light returning toward the detector is the one that carries the OCT information.