Setting the parameters II

[Mehdi_Kazemi]

How to properly set the Nx, Ny, Nz, Nt and the respective step size and time windows?
What is the relation between those parameters, crystal (material) length, pulse duration and propagation time of the pulse through the crystal?

[tinolang]

There are several options which can lead you to the best sampling parameter.

1)
To understand what is going on you can calculated it by hand. Usually you know the necessary temporal window and the spectral with to include all input pulses and mixing products. The temporal window and the spectral window are connected as following:

max sampling frequency = 1/dt
whereas the min sampling frequency is 1/temporal window which is in the THz spectral range. This frequency window can be shifted by obj.simProp.shiftFreqWindow to save computation time. This leads to the following relation:
dt=1/(3e8/lambdaMin-3e8/lambdaMax)

Nt is then your temporal window divided by dt

The Nx and Ny depends on the spatial window and the maximum nonlinear propagation you want to sample

fxMax=sin(alphaMax)*n/lambdaMax;
dx=1/fxMax;
Nx=spaceMax/dx;

As an alternive you can use two methods of chi3D which can do the job for you:
obj=chi3d;
obj.minNtime.help
obj.minNspace.help

2) You can also play around with chi2D and check out which sampling gives you reasonable results.
 
The results should not depend on the sampling. This is also true for Nz. Increase Nz till the output parameter are not depending on it anymore.