ZBF is file describing a beam's 2D energy distribution exported by Physical Optics Propagation (POP) in OpticStudio. This file can be further imported to Lumerical to do further simulation.

When importing th ZBF to Lumerical, users might see an error shows as below:

'Error: the file data had unacceptable values.'

In this case, it means the ZBF doesn't include electric field information (Ex, Ey). We can generate a ZBF with eletric field information by

(1) Check the 'Use Polarization' in POP.

(2) Go to System Explorer, uncheck 'Unpolarized' and set up an polarization. It's suggested to run POP twice for X and Y polarizied beams to fully consider both polarization.