Interferometric analysis of laser-driven cylindrically focusing shock waves in a thin liquid layer

Abstract

Shock waves in condensed matter are of great importance for many areas of science and technology ranging from inertially confined fusion to planetary science and medicine. In laboratory studies of shock waves, there is a need in developing diagnostic techniques capable of measuring parameters of materials under shock with high spatial resolution. Here, time-resolved interferometric imaging is used to study laser-driven focusing shock waves in a thin liquid layer in an all-optical experiment. Shock waves are generated in a 10 µm-thick layer of water by focusing intense picosecond laser pulses into a ring of 95 µm radius. Using a Mach-Zehnder interferometer and time-delayed femtosecond laser pulses, we obtain a series of images tracing the shock wave as it converges at the center of the ring before reemerging as a diverging shock, resulting in the formation of a cavitation bubble. Through quantitative analysis of the interferograms, density profiles of shocked samples are extracted. The experimental geometry used in our study opens prospects for spatially resolved spectroscopic studies of materials under shock compression.

Single-bubble and multibubble cavitation in water triggered by laser-driven focusing shock waves

“…1(a). A 150ps duration, 800-nm wavelength, laser pulse delivered by an amplified Ti:sapphire system is focused into a 10 µmthick liquid layer as described in [11][12][13]. The thin liquid layer consists of a suspension of carbon nanoparticles in water (India ink diluted to yield 2% weight carbon concentration).…”

“…where a picosecond laser pulse shaped into a ring [11][12][13][14] is focused into a thin absorbing liquid sample to create high amplitude converging shock waves and cavitation bubbles. This configuration enables the generation of localized high pressure away from the laser focus, contrarily to classical laser cavitation experiments [16][17][18], and the real-time observation of propagating shock waves as well as dynamics of cavitation bubbles.…”

“…In the present work, we expand the initial study on laser ring excitation [11][12][13] by exploring longer time delays in order to observe the dynamics of nucleated bubbles. We also model the shock wave propagation and focusing to quantify the effect of the laser ring radius on the negative pressure reached at the center.…”

Picosecond-resolution phase-sensitive imaging of transparent objects in a single shot

“…Moreover, with the growing interest in optical detection of neuronal action potentials, the field of phase imaging has started to seek a marked improvement in speed to match the propagation speed of neuronal action potentials (33)(34)(35). Recently, several techniques have succeeded in detecting ultrafast phase signals, including the light-in-flight recording by digital holography (LIF-DH), the time-resolved holographic polarization microscopy (THPM), and the ultrafast framing camera (UFC) (36)(37)(38)(39)(40). Although these techniques achieve high-frame rate imaging, their sequence depths (i.e., the number of frames per movie) are limited by several factors, such as the number of imaging pulses (THPM), the trade-off between the sequence depth and the field of view (LIF-DH), and the number of array detectors (UFC).…”

Acoustical breakdown of materials by focusing of laser-generated Rayleigh surface waves

“…In this work, high-amplitude focused SAWs are generated by ring-shaped laser pulses in an arrangement resembling the one that was used to focus shock waves in a thin liquid layer 18,19 and in highly-ordered pyrolytic graphite. 20 The "acoustical breakdown" takes place at the focal point in the linear regime of the SAW propagation.…”