
THG Microscopy of Cells and Tissues 61
If we now consider the case of an interface along the x or y axis (Figures 3.7b and 3.7c), the emission
diagrams evolve from a single-peaked emission in the case of an interface perpendicular to the optical
axis, to the aforementioned symmetric double-peaked emission in the case of an interface parallel to the
optical axis, with intermediate positions showing an asymmetric double-peaked emission.
is orientation dependence can be conrmed experimentally by imaging the top corners of a glass
coverslip (Figure 3.8a). In this geometry, signals from glass/water interfaces with three dierent orienta-
tions c