(color online) (a) Far field spot with segmented mirror de-focused and (a1) the intensity of far field spot with segmented mirror de-focused; (b) the far field spot with 2 sub-mirrors co-focused and (b1) the intensity of far field spot with 2 sub-mirrors co-focused; (c) the far field spot with 3 sub-mirrors co-focused and (c1) the intensity of far field spot with 2 sub-mirrors co-focused; (d) the far field spot with 4 sub-mirrors co-focused and (d1) the intensity of far field spot with 4 sub-mirrors co-focused.