A multi-layer polarization grating includes a first polarization grating layer, a second polarization grating layer on the first polarization grating layer, and a third polarization grating layer on the second polarization grating layer, such that the second polarization grating layer is between the first and third polarization grating layers. The second polarization grating layer has a periodic molecular structure that is offset relative to that of the first polarization grating layer along an interface therebetween. The third polarization grating layer may also have a periodic molecular structure that is offset relative to that of the second polarization grating layer along an interface therebetween. As such, the periodic molecular structures of the first and second polarization grating layers may be out of phase by a first relative angular shift, and the periodic molecular structures of the second and third polarization grating layers may be out of phase by a second relative angular shift. Related fabrication methods are also discussed.