Study of Intense Femtosecond Radiation Scattering during Optical Breakdown of Water

• Published in: Bulletin of the Lebedev Physics Institute 2023-12, Vol.50 (Suppl 10), p.S1092-S1099
• Main Authors: Kononenko, V. V., Dezhkina, M. A., Kononenko, T. V., Konov, V. I.
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Breakdown; Cavitation; Distilled water; Energy dissipation; Femtosecond pulses; Interaction of Laser Radiation with Matter; Lasers; Physics; Physics and Astronomy; Scattering
• ISSN: 1068-3356; 1934-838X
• DOI: 10.3103/S1068335623220062

We examine radiation scattering in the region of laser breakdown initiated in distilled water by a sequence of intense femtosecond pulses (Ti:Al 2 O 3 laser, wavelength 800 nm, repetition rate 1 kHz). The pulse energy varies from 1 μJ to 1 mJ, while the process of bubble formation (liquid cavitation regime) is maintained throughout the specified range. Each pulse is a train with a period of ∼10 ns and, in addition to the main pulse (∼150 fs), contains several prepulses and postpulses with a contrast of ∼70. The dependence of the breakdown region shape and size at different laser energies is studied. Spectra of scattered radiation and the dependence of its intensity on laser energy are obtained for both the main pulse and accompanying ones. The specific features of radiation energy dissipation in water at ultra-high laser radiation intensities and the contribution of accompanying pulses to this process are analyzed.