<p>An optical pickup is capable of projecting laser beams having different polarization directions or different divergence angles from laser sources formed in a surface emitting laser array and varying the effective numerical aperture of an optical system provided with an objective lens and the like. The optical pickup has a high-degree compatibility with both a CD-standards optical disk having a low recording density and a large thickness and a DVD-standards optical disk having a high recording density and a small thickness. Furthermore, a plurality of laser sources can be formed in a compact space by adopting the surface emitting laser array, and the numerical aperture of the optical system can be controlled by making a selection of laser beams. Accordingly, it is possible to realize an optical pickup having compatibility by means of an extremely simple construction, and it is also possible to inexpensively provide a small-size high-performance optical pickup.</p>
