Figure 1

A schematic diagram of the experimental setup. 1. $Q$-switched Nd-YAG laser, 2. piezoelectric shock wave generator, 3. optic fiber of the FOPH 500 mounted on a 3D translation stage, 4. water tank, 5. beam expander, 6. focusing lens.Reuse & Permissions

Figure 2

Time variation of (a) bubble diameter and (b) bubble wall velocity. Solid lines are theoretical predictions based on the Raleigh-Plesset model and dots are experimental measurement results from high-speed photography. $D$: diameter of the bubble; $\dot{D}$: wall velocity. $E$ expanding, $S$ standing, $C$ collapsing bubbles.Reuse & Permissions

Figure 3

High-speed images of the interaction between lithotripter shock wave (LSW) and laser-generated single bubbles at different phases of the bubble oscillation. Interframe time is $0.5\mu \mathrm{s}$, exposure time for each image frame is 10 ns, frame width is 0.7 mm. Laser light comes from the right. The LSW (not visible at this output level) propagates from the bottom to the top of the image frame and impinges on the bubble in the third frame. The interpulse delay is (a) 3, (b) 6, (c) 29, (d) 50.5, and (e) $53.5\mu \mathrm{s}$, respectively. The corresponding bubble diameter at the moment of LSW impact is (a) 0.32, (b) 0.39, (c) 0.64, (d) 0.40, and (e) 0.31 mm, respectively. Arrows point to secondary shock wave emission.Reuse & Permissions

Figure 4

(a) The ratio of vertical over horizontal diameters for the type $E$ bubble [Fig. 3b] and the type $C$ bubble [Fig. 3d]. Pressure waveforms measured at $z_p=1.1\mathrm{mm}$ following lithotripter shock wave-bubble interaction for (b) the type $E$ bubble and (c) the type $C$ bubble of the same size. $P_{+}{}^{\prime }$ and $T_{+}{}^{\prime }$ are peak pressure and zero-crossing duration of LSW with bubble, $P_c{}^{\prime }$ and $\tau _c{}^{\prime }$ are peak pressure and FWHM of the second shock wave from the forced collapse of laser-generated bubble by the LSW, and $T_c{}^{\prime }$ is the forced collapse time.Reuse & Permissions

Figure 5

Normalized (a) peak pressure, (b) FWHM, and (c) collapse time versus normalized bubble diameter when lithotripter shock wave-bubble interaction occurs at the expanding ($E$), standing ($S$), and collapsing ($C$) phase of the bubble oscillation. Error bars show the standard deviation of the measurement data. Quadratic fits of the experimental data are shown in dashed lines (type $E$ bubbles) and solid lines (type $C$ bubbles). Dotted lines are hypothetical curves.Reuse & Permissions