Fig. 3.

Wideband detection of cavitation events using a PVDF detector. Lasing time is shown with the red dotted line and the ultrasound 10-cycle pulse travels to the focus starting from the blue dotted line time. (a)–(c) Signals after differentiation. (a) and (b) No cavitation and cavitation (probability 5%) with exposures of F₀ = 0.641 mJ/cm², p− = 1.74 MPa. (c) Large cavitation (F₀ = 4.7 mJ/cm², p− = 1.43 MPa). (d) Normalized spectra of differential signals for large (red), small (orange) and spectrum of the driving signal at 1.24 MHz.