S.N. HoseinimotlaghM.S. SharifiKh. Shoja Department of Physics, Islamic Azad University, Shiraz branch, Shiraz, IranTeacher of Education Office, Fars, Sepidan, IranDepartment of Physics, Islamic Azad University, Science and Research Branch, Fars, Iran hoseinimotlagh@hotmail.com International Journal of Fundamental Physical Sciences (IJFPS) 4 1 26-36 March, 2014 2231-8186 https://doi.org/10.14331/ijfps.2014.330063 This study explores the interaction of ultra-short pulsed lasers with water and skin tissue, aiming to understand ablation dynamics for potential cancer treatment. A cylindrical 2D and 3D model is used to compute time-dependent free-electron density using the Runge-Kutta method. Results show optimal ablation occurs in the dermis layer at angles 16° and 22°, with electron density increasing with radiation intensity and decreasing focal distance. The analysis confirms chromophore ionization and cascade mechanisms as the primary contributors to plasma generation. The study concludes that skin tissue produces more free electrons than water under identical conditions. laser, plasma, electron, ultra short https://creativecommons.org/licenses/by/4.0/