MODEL OF LASER INTERACTION WITH LIQUID DROPLET

Subject of Research. A mathematical model of optical breakdown in the dielectric liquid droplets when exposed to pulsed laser radiation was developed. The process is considered in several stages: heating, evaporation of the particle, forming a steam halo, ionization of the steam halo. Numerical stud...

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Bibliographic Details
Main Authors: K. N. Volkov, P. V. Bulat, E. E. Il'ina
Format: Article
Language:English
Published: Saint Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University) 2016-09-01
Series:Naučno-tehničeskij Vestnik Informacionnyh Tehnologij, Mehaniki i Optiki
Subjects:
Online Access:http://ntv.ifmo.ru/file/article/16074.pdf
Description
Summary:Subject of Research. A mathematical model of optical breakdown in the dielectric liquid droplets when exposed to pulsed laser radiation was developed. The process is considered in several stages: heating, evaporation of the particle, forming a steam halo, ionization of the steam halo. Numerical study was carried out on the basis of the mathematical model to determine the threshold characteristics of the laser pulse. Main Results.Distributions of pressure, density and temperature of the particle steam halo were obtained by means of a calculation. The temperature field around the liquid droplet was determined. It has been found that at high energies in the gas bubble, the conditions are provided for thermal gas ionization and start of the electron avalanche, leading to plasma formation. Due to the volumetric heat generation, the droplet is overheated and is in a metastable state. The plasma cloud is almost opaque to radiation that causes an abrupt increase of temperature. As a result, an explosion occurs inside the droplet with the formation of a shock wave that is propagating outward. Practical Relevance.The results can be used to assess the performance of high-power laser scanning (LIDAR) under the presence of liquid droplets in the atmosphere and other suspensions. Lasers can be used in fire and explosion aerospace systems. Obtained findings can be applied also in the systems of laser ignition and detonation initiation.
ISSN:2226-1494
2500-0373