This is a new topic and we have no similar example.
You may use sweep to get some data of the phase change vs geometry and polarization for given material and periodicity. Using those data to train the AI. later when you specify the phase desired it may give you possible geometry and periodicity.
please refer the sweep: https://optics.ansys.com/hc/en-us/articles/360034922873-Parameter-sweep-utility
then using script getsweepresult, and reognaze the data to feed the deep leaning.