The following are some calculator that will help you calculate the Energy fluence (in Joules per centimetre square) and the Peak Intensity (in Watts per centimetre square)

by inputting the value of Pulse Energy (in Joules) ,Beam radium at $\frac{1}{e^2}$ intensity (in centimetre) and Pulse duration (in second).

www.simtrum.com

Input
Pusle Energy,$\ E$:
J
Beam radium at 1/e$^2$ intensity, $\omega$:
cm
Pulse duration, $\tau$:
fs


Output
Peak Intensity:
GW/cm$^2$
Energy fluence, $\ F$:
J/cm$^2$