When I open a poup ,Can it open Maximize default?
Opening maximized is akin to opening a new tab. Have you considered using system.perspective.navigate(page="XYZ", newTab=True)
while supplying the arguments which would open the specified page in a new tab?
If you must open a Popup in full screen (which I personally consider to be a poor design choice), you'll want to look into using the dimensions of the viewport when specifying the width of the Popup.