BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements numbered alike in several Figures, in which:
FIG. 1 illustrates a block diagram of the structure for the optical pickup apparatus PU1 of an embodiment of the present invention, which is capable of appropriately recording/reproducing information for different optical information media, such as HD, DVD and CD;
Each of FIGS. 2(a) and 2(b) is a cross sectional view showing an example of the diffractive structure;
Each if FIGS. 3(a) and 3(b) is a cross sectional view showing an example of the diffractive structure; and
FIG. 4 is a cross sectional view showing an example of the objective lens OBJ of the embodiment.