Figure 3.

(a) Topography and (b) SHG images of another sample. (c, d) SHG polarization polar maps with the polarizer and analyzer parallel (black) and crossed (red) acquired at the black square (N = 4) and white circle (N = 6) in (b), respectively. The crystallographic axes are shown in (a). The angle in the polar plots is relative to the initial polarization, shown as a white double arrow (b). Scale bar = 3 μm.