A grid polarizer including an array of groups of parallel elongated ribs disposed over a substrate. Each group of elongated ribs can comprise at least four ribs. Tops of two center ribs, at a center of each group, can be substantially the same elevational height and can be higher by more than 10 nm than tops of outer ribs of the groups. A region between adjacent ribs can have an index of refraction substantially equal to one. Some or all of the ribs can comprise polarizing wires disposed over substrate rods.