Article
Optics
Y. L. Zhao, H. L. Yin, J. C. Shi, S. N. Luo
Summary: Nanosecond time-resolved schlieren imaging was used to study laser-induced breakdown in ni-tromethane, nitroethane and 1-nitropropane, as well as the dynamics of associated shock waves and cavitation bubbles. The increase in shock wave velocity is due to exothermic reactions during decomposition and chemical reactions in the vapor plume behind the shock front. Correlations between oxygen balance and shock wave velocity, bubble radius, lifetime and bubble energy are established. For example, shock wave velocity is proportional to the negative inverse of oxygen balance. Additionally, the bubble energy of nitroethane saturates at high pulse energy.
OPTICS AND LASERS IN ENGINEERING
(2023)
Article
Acoustics
Darja Horvat, Vid Agrez, Tomaz Pozar, Bojan Starman, Miroslav Halilovic, Rok Petkovsek
Summary: This study investigated the generation of secondary cavitation following laser-induced breakdown in spherical media. Through numerical simulation and experimental comparison, it was found that significant transient negative pressure and pre-illumination by breakdown-generating laser pulses played important roles in the generation of secondary cavitation.
ULTRASONICS SONOCHEMISTRY
(2022)
Article
Mechanics
R. T. Cerbus, H. Chraibi, M. Tondusson, S. Petit, D. Soto, R. Devillard, J. P. Delville, H. Kellay
Summary: The generation of liquid jets and drops near a liquid-air interface using femtosecond laser pulses involves the nucleation of cavitation bubbles and the emergence of two distinct jets. The first jet is thin and fast, produced during the initial expansion of the bubble, while the second jet is thick and slow, emanating from the surface as the bubble deflates. The mechanism behind this phenomenon has been investigated using experiments and simulations, revealing that the second jet is not a result of bubble expansion but originates from the secondary flows induced by the bubble dynamics. A phase diagram has been established to understand the emergence of the second jet by linking its properties to the control parameters of the problem.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Acoustics
Haigang Wen, Zhifeng Yao, Qiang Zhong, Ye Tian, Yurong Sun, Fujun Wang
Summary: In this study, highly spherical cavitation bubbles were generated using nanosecond laser pulses, and the evolution and energy partitioning of the bubbles were investigated. The results showed that the ratio of shock wave energy to bubble energy varied at different stages, providing important insights into the formation mechanism of shock waves.
ULTRASONICS SONOCHEMISTRY
(2023)
Article
Acoustics
Mohammad Khavari, Abhinav Priyadarshi, Justin Morton, Kyriakos Porfyrakis, Koulis Pericleous, Dmitry Eskin, Iakovos Tzanakis
Summary: This paper investigates the effects of different liquid physical properties on shock wave characteristics. The experiments were conducted using ethanol, glycerol, and a 1:1 ethanol-water solution as substitutes for water. The results show that ethanol and glycerol barely exhibited a shock wave pressure peak, particularly at low input powers, while the 1:1 ethanol-water solution and water consistently showed the presence of a shock wave pressure peak.
ULTRASONICS SONOCHEMISTRY
(2023)
Article
Mechanics
Xiao-Xuan Liang, Norbert Linz, Sebastian Freidank, Gunther Paltauf, Alfred Vogel
Summary: The dynamics of spherical laser-induced cavitation bubbles in water were investigated using experimental techniques and numerical simulations. The study revealed the oscillation characteristics, gas content, and shock wave emission of the bubbles, and analyzed the motion velocity of the bubble wall and energy distribution.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Marine
Yanwei Zhai, Weilin Xu, Jing Luo, Jianbo Li
Summary: This paper studies the interaction between cavitation bubbles and different elastic boundaries from the perspective of microjets and shock waves. The elastic deformation characteristics of elastic materials under the penetration of microjets are found to be the main influencing factors of cavitation erosion.
Article
Materials Science, Multidisciplinary
Justin A. Morton, Mohammad Khavari, Ling Qin, Barbara M. Maciejewska, Anastasia Tyurnina, Nicole Grobert, Dmitry G. Eskin, Jiawei Mi, Kyriakos Porfyrakis, Paul Prentice, Iakovos Tzanakis
Summary: By observing the impact of ultrasound and acoustic cavitation on the exfoliation process of graphite in real-time, the dynamic sequence of graphite layer exfoliation was revealed. The generation of pressures up to 5 MPa and liquid jet velocities of 80 m/s were found to be crucial for the initiation and propagation of the exfoliation process, while bubble oscillations associated with stable cavitation were beneficial for promoting a gentler delamination of graphite layers.
Article
Acoustics
Fabian Reuter, Carsten Deiter, Claus -Dieter Ohl
Summary: This study reveals the mechanism behind energy focusing during the non-spherical collapse of cavitation bubbles, leading to the erosion of hardened metals. Using high-speed imaging and shockwave recording, the conditions for this focusing process and its damage to solids are resolved.
ULTRASONICS SONOCHEMISTRY
(2022)
Article
Acoustics
Hossein Haghi, Michael C. Kolios
Summary: This study examines the effect of bubble-bubble interactions on the resonance frequency of MB suspensions. It is found that primary delays cause spreading the resonance frequency of identical MBs within a range, where the closest MB to the acoustic source exhibits the lowest resonance frequency and the furthest MB resonates at the highest frequency. The inclusion of secondary delays also significantly affects the resonance frequency, resulting in an increase when the MBs are situated close to each other.
ULTRASONICS SONOCHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Konstantinos Kaleris, Bjoern Stelzner, Panagiotis Hatziantoniou, Dimosthenis Trimis, John Mourjopoulos
Summary: This work introduces a novel laser-based optoacoustic transducer that can reproduce arbitrary complex sound in the air or on solid targets without the need for a receiver or demodulation device. The performance of the prototype is evaluated through experimental measurements and a computational model, with good agreement found between model evaluations and acoustic measurements. Additionally, a generic computational model is presented for simulating different types of audio streams.
SCIENTIFIC REPORTS
(2021)
Article
Mechanics
Ulisses J. Gutierrez-Hernandez, Fabio De Colle, Claus-Dieter Ohl, Pedro A. Quinto-Su
Summary: In this work, a Fresnel-lens-inspired method is proposed and demonstrated for focusing multiple laser-induced shock waves through time-delay superposition at arbitrary locations. The method has been successfully demonstrated experimentally, showing effectiveness under specific geometric conditions and good agreement with simulation results.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Acoustics
Dui Qin, Qingqin Zou, Shuang Lei, Wei Wang, Zhangyong Li
Summary: The cavitation-mediated bioeffects are mainly related to the dynamic behaviors of bubbles in viscoelastic tissues. The interactions between two interacting cavitation bubbles in such tissues have significant effects on acoustic emissions. Increasing the initial distance between bubbles enhances the nonlinear dynamics of bubbles.
ULTRASONICS SONOCHEMISTRY
(2021)
Article
Acoustics
Vid Agrez, Jaka Mur, Jaka Petelin, Rok Petkovsek
Summary: For the first time, the nucleation and growth of micrometer-sized cavitation bubbles in water generated by a 60 ps 515 nm fiber laser were observed and visualized. Two types of cavitation events were identified and visualized, showing a significant difference in excitation energy converted to mechanical effects. This finding has potential positive implications for laser treatments of biological tissue.
ULTRASONICS SONOCHEMISTRY
(2023)
Article
Engineering, Marine
Zhenkun Tan, Mindi Zhang, Guohao Huang, Biao Huang
Summary: This paper investigates the collapse behavior of cavitation bubble near an air bubble using high-speed photography and schlieren optical method. The analysis of data such as bubble collapse time, collapse position, and the velocity of collapse jet reveals distinct patterns and dynamic features. Compared to cases without air bubble merger, the collapse jet velocity and shock wave intensity are significantly smaller when the cavitation bubble merges with the air bubble. Understanding the influence of air bubble on cavitation bubble has great significance in reducing cavitation damage.
Article
Optics
G. A. S. Flizikowski, O. A. Capeloto, V. G. Camargo, B. Anghinoni, M. L. Baesso, L. C. Malacarne, M. P. Belancon, T. Pozar, N. G. C. Astrath
Article
Optics
Vid Agrez, Tomaz Pozar, Rok Petkovsek
Article
Biochemical Research Methods
Tomaz Pozar, Rok Petkovsek
BIOMEDICAL OPTICS EXPRESS
(2020)
Article
Materials Science, Multidisciplinary
D. Horvat, T. Pozar, B. Starman, M. Halilovic, R. Petkovsek
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2020)
Article
Acoustics
Tomaz Pozar, Zan Pirc, Egon Susic, Rok Petkovsek
Article
Physics, Applied
G. A. S. Flizikowski, B. Anghinoni, J. H. Rohling, M. P. Belancon, R. S. Mendes, M. L. Baesso, L. C. Malacarne, T. Pozar, S. E. Bialkowski, N. G. C. Astrath
JOURNAL OF APPLIED PHYSICS
(2020)
Article
Optics
Jaka Petelin, Luka Cerne, Jaka Mur, Vid Agrez, Jernej Jan Kocica, Joerg Schille, Udo Loeschner, Rok Petkovsek
Summary: In this manuscript, two different approaches are presented for a true pulse-on-demand laser design concept. One approach is a fiber MOPA-based quasi-CW laser for nanosecond pulses, while the other is a hybrid CPA-based laser for femtosecond pulses. The pulse-on-demand operation is achieved without an external optical modulator/shutter at high-average powers, with the nanosecond laser source being applied to high throughput processing of thin film materials.
ADVANCED OPTICAL TECHNOLOGIES
(2021)
Article
Engineering, Mechanical
Klemen Zaletelj, Vid Agrez, Janko Slavic, Rok Petkovsek, Miha Boltezar
Summary: The proposed method utilizes laser-light interference to form a speckle pattern for DIC measurements without modifying the surface of the structure, with speckle size depending on factors such as surface roughness.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Biochemical Research Methods
Jaka Mur, Vid Agrez, Jaka Petelin, Rok Petkovsek
Summary: This study focuses on the influence of boundaries on the dynamics and morphology of cavitation bubbles, particularly the observation and measurement of jetting behavior near tissue-phantom biointerfaces. The researchers used time-resolved optical microscopy to observe the important mechanism of boundary poration and explained it for different tissue-phantom surface densities and Young's modulus.
BIOMEDICAL OPTICS EXPRESS
(2022)
Article
Optics
Matevz Mars, Rok Petkovsek, Vid Agrez
Summary: This paper presents a method for directly controlling the pulse on demand operation of an intracavity frequency doubled Nd:YVO4 laser. It can generate arbitrary delay between pulses in the output sequence with an upper limit in the MHz range. Micro pulses on demand were achieved through the optimization between conversion efficiency and achievable repetition rate using the gain switching technique and intracavity doubling. Additionally, the study demonstrates a high modulation intracavity doubled Nd:YVO4 laser utilizing the crystals high emission cross section for fast gain switching. In the experimental setup, the highest repetition rate over 2 MHz and frequency doubling efficiency of 30% were achieved, with further scaling possible using optically bonded tightly packed architecture. The pulse on demand operation of a compact micro pulsed laser at 532 nm enables full synchronization with the application.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Optics
Jaka Mur, Fabian Reuter, Jernej Jan Kocica, Ziga Lokar, Jaka Petelin, Vid Agrez, Claus-Dieter Ohl, Rok Petkovsek
Summary: This paper presents a multi-frame multi-exposure shock wave velocity measurement technique that can measure the propagation speed of shock waves in different directions, verified by a fiber-optic probe hydrophone. The experimental results show that the pressure is higher at closer distances to the plasma center.
Article
Acoustics
Darja Horvat, Vid Agrez, Tomaz Pozar, Bojan Starman, Miroslav Halilovic, Rok Petkovsek
Summary: This study investigated the generation of secondary cavitation following laser-induced breakdown in spherical media. Through numerical simulation and experimental comparison, it was found that significant transient negative pressure and pre-illumination by breakdown-generating laser pulses played important roles in the generation of secondary cavitation.
ULTRASONICS SONOCHEMISTRY
(2022)
Article
Acoustics
Vid Agrez, Jaka Mur, Jaka Petelin, Rok Petkovsek
Summary: For the first time, the nucleation and growth of micrometer-sized cavitation bubbles in water generated by a 60 ps 515 nm fiber laser were observed and visualized. Two types of cavitation events were identified and visualized, showing a significant difference in excitation energy converted to mechanical effects. This finding has potential positive implications for laser treatments of biological tissue.
ULTRASONICS SONOCHEMISTRY
(2023)