•Laser induced absorption phenomena in transparent materials are simulated.•A simulation tool to be used for accurate prediction of laser breakdown is proposed.•Time shapes of total electron density and photoionization generated electrons density are calculated. The laser-induced damage in transparent optical materials represents an important active field of research as part of laser/material interactions studies. Most of research activities within this field are aiming to laser micro-processing of transparent optical materials, glasses and ceramics. An example of such laser micro-processing techniques is drilling micro channels through a glass plate and drilling transverse holes through single mode optical fibre cladding and core. The latter example of research activity has an important purpose consisting of designing and manufacturing micro-nanoscale optical fibre sensors with improved capabilities. Regarding these applicative research activities, there are two important correlated issues here to be underlined. The first one consists in the fact that high intensity laser field induced electron density variation into a transparent material is the main mechanism of breakdown and damage, that is, basis of micro-processing. The second one refers to the necessity of developing simulation procedures based on accurate theoretical models of these physical processes in order to use an accurate computer control of micro-processing technology. The main purpose of this work is to present the results of simulations in electron density variation induced by high intensity laser pulses in various transparent materials.