Optical pickup.

摘要

An optical pickup is used to optically read recorded information on an optical information storage medium such as a compact disk (20) in a compact disk player, for example. The optical pickup has a beam splitter (2) having a first facet (21) for reflecting a laser beam from a semiconductor laser (1) toward the optical information storage medium. The right beam reflected from the optical information storage medium passes through and is diffracted by the first facet (21) of the beam splitter (2). The laser beam then passes through a second facet (22) of the beam splitter (2), and is then divided by a diffraction grating (3) into a transmitted beam and a diffracted beam that is then guided through an optical waveguide (4). The beam splitter is simple in structure and can easily be manufactured, and hence the optical pickup is relatively small in size. Another optical pickup includes a phase layer (8), a polarizer layer (9), and a diffraction grating (3) in a semiconductor substrate (1). A laser beam reflected by an optical information storage medium is caused to change the phase by the phase layer (8), and passes through the polarizer (9) layer to the diffraction grating (3), which divides the laser beam into a transmitted beam and a diffracted beam. The phase layer (8) and the polarizer layer (9) are fabricated at the same time that the semiconductor substrate (1) is manufactured.