Figure 2. Computed wave propagation and focus change when the lens size is changed.

(a) Light focuses at 7 mm after it propagates through the lens; (b) When the lens is radially stretched by 10%, light redistributes and focuses at around 8.47 mm; (c) The light intensity along the z-axis of the focal plane, shows a clear shift of the peak intensity, indicating a focal point change from f to f′.