Fig. 3.

Fig. 3.

(a)–(c) and (d)–(f) show the B-scans and en face images of the phantom, respectively. In (a)–(c), the orange arrowheads denote the approximate focal positions, and the yellow boxes denote a deep region of the scattering layer. In (d)–(f), the magnification insets are the en face images of a small region in the scattering layer containing several scatterers. In (d), the red circles denote the scatterers selected to compute the signal intensity. The blue line indicates a region with 2 × 200 A-lines in the glass plate region used to compute the background intensity for the SBR analysis, and their locations in the B-scans are indicated by the blue bracket in (a). White arrows in (d)-(f) indicate a low-intensity scatterer signal, which is dimmed in (f). It could be the speckle caused by the MS signal. (g) shows the intensity depth profiles that are averaged by the A-lines at the en face locations denoted by the blue line in (d). The 0-mm depth refers to the top surface of the cover glass on the top, and the green arrowhead denotes the depth in air where the intensity is 0 dB. The orange arrowheads in (a) and (g) denote the depth where the en face images are taken.