An optical element includes a liquid crystal layer; and at least one alignment layer in contact with the liquid crystal layer, the at least one alignment layer being formed from a mixture including a first reactive mesogen and a second reactive mesogen. Each of the first and second reactive mesogens have at least one polymerizable functional group, and a number of polymerizable functional groups of the second reactive mesogen is smaller than that of the first reactive mesogen. A ratio of the second reactive mesogen to the first reactive mesogen in the mixture is determined so as to provide a predetermined pretilt angle with liquid crystal molecules in the liquid crystal layer.