Imaging of shock wave and cavitation bubble dynamics in laser-induced ablation in liquids with ultrahigh spatiotemporal resolution (Conference Presentation)

Laser-induced ablation in liquids involves a sequence of plasma formation, shock wave emission, and bubble oscillations with large range of spatial and temporal scales, which makes the experimental investigation challenging. We imaged laser ablation in side view using a water immersion microscope objective with high numerical aperture. For speckle-free imaging, 10-ps laser pulses at 515 nm wavelength were coupled into a sequence of 50-µm graded-index and 600-µm step-index multimode fiber. With optimized fiber length, spectral broadening and spatial mode mixing provides speckle-free illumination enabling to freeze bubble and shock wave dynamics at diffraction-limited resolution with 37 ps exposure time.