Fig. 1. Schematic of the dual-beam delay-encoded fiber-based DOCT system. L1–L10, lens; L11, cylindrical lens; M1, mirror; M2, strip mirror; D1, D2, dichroic mirror; C1, C2, line scan camera; FC, fiber coupler; PC, polarization controller; F, fixation screen; GP, glass plate; BD, beam displacer; LD, 780 nm laser diode; LSLO, line scanning laser ophthalmoscopy system; SLD, superluminescent diode.

Fig. 2. Illustration of the incident probe beams and the blood flow velocity. V, direction of the blood flow velocity; P₁ and P₂, two probe beams; Δα, angle between the two probe beams; β, angle between V and the illumination plane (y–z plane, composed of P₁ and P₂).

Fig. 3. Illustration of the illumination plane and scanning track. V, direction of the blood flow velocity; L, scanning track of OCT beams on the retina.

Fig. 4. (a) Measured blood flow at the set blood flow of 20 µL/min as a function of the sampling step. (b) Measured blood flow versus the set blood flow.

Fig. 5. Retinal blood flow imaging with the DDD-OCT system. (a) LSLO fundus view. The black line marks the scanning track. V₁, an artery vessel. (b) Structural and (c) Doppler OCT images of the vessel V₁. (d) Absolute velocity of the blood flow in V₁ as a function of time.