I am modeling a non-linear phenomenon. For that i need to calculate electric field distribution of a laser beam. I will be using pulsed laser beam with following parameters: " Laser pulse with 500-microJ pulses(Ep) at 1.064 micro-m with 12.5-KHz (f) repetition rate, pulse duration = 20 ns (2*T), and beam radius = 0.2 mm (w) " From this data i need to calculate, Intensity distribution and from there i need to calculate Electric field distribution both of which are Gaussian in nature. I have done this as follows: First the peak power = (pulse energy)/Pulse duration = 500μJ/20ns = 25 KW. Now, taking beam radius to be 200μm, Peak Intensity (Io) = 25 KW/(π*w^2)= 19.89 MW/cm^2; Now as i know that the distribution is Gaussian, I am using the following equation for creating the distribution. I = Io*exp(-(t/T)^2)*exp(-(r/w)^2) Now, I = (cnεo *|E|^2)*0.5 I would like to ask if the above calculation is right. I thank you for your valuable time.