Laser Diffraction Imaging of Highly Ionized Plasma Microchannels in a Pulsed Nanosecond Gas Discharge

Abstract

We discuss the key principles of laser diffraction imaging of plasma microchannels with a high degree of ionization, arising during a pulsed nanosecond gas discharge and registered at a wavelength of 1064 nm. The direct problem of laser radiation diffraction on a model plasma microchannel is solved numerically, and the propagation of diffracted radiation in an optical lens system up to the image plane of the object is described. Important properties of diffraction patterns of plasma microchannels obtained in the optical lens system are demonstrated, which can be used for their processing and subsequent accurate reconstruction of the plasma permittivity distributions. The results can be of wide interest for the development of new precision methods for optical imaging of rapidly evolving phase micro-objects.