I would like to know how to set the power and diameter of the incident Gaussian beam?

[chaoyuhui]

I mean, setting the incident optical power is not the set energy divided by the TFWHM. Because when I use this program to simulate, many literature give the parameter is power.

[sudipsharma032-jpg]

I am using the relation
Pulse energy (Ep)= Pp(Peak power) in Watts * TFWHM(sec)/(0.94)

In this regard,If the peak power of a pulse is 5W with FWHM of 90 ps , the corresponding energy value will be 0.9574nJ.

[sudipsharma032-jpg]

In the best of my knowledge, we can't incorporate the beam diameter of input beam into our discussion here in this code. We assume that whatever light is being launched on 25 um radius GRIN fiber goes through it.

In other words, the beam dia is anyway always less than 50um or so.