Hi Guilin, 

Thank you for reply.

1) Can you refer me to a similar example of designing DOE in Lumerical? I wish to design element that shapes the input beam by phase variation (achieved by surface relief i.e

    surface of many different features with different heights) and not by index variation (done by metalens). 

2) Will I be able to export my design into GDS or PNG files?

Best Regards,