Signal acquired in LC-OCT from the test sample shown in Figure 4. The parameters are: λ₀ = 750 nm, ∆λ = 200 nm, z_S = 200 μm, n_im = 1.40, n_glass = 1.45, NA = 0.5. R_ref = 0.19%. Three values of the refractive index n are considered (1.33, 1.40, 1.51). (a–c) Simulations based on equation (25). (d–f) Experiment. The peak corresponding to the focus on interface 2 coincides with the center of interference fringes only when n_im = n ((c) and (f)).