OPTICAL PICKUP DEVICE AND OPTICAL DISC APPARATUS APPLYING THE SAME

PROBLEM TO BE SOLVED: To provide an optical pickup capable of making a circular shape of a light spot with respect to light from a semiconductor laser light source and capable of reducing jitter or crosstalk.SOLUTION: An optical pickup device 100 comprises a polarization plate 59 which is disposed on an optical path between a semiconductor laser light source 20 and an objective lens 30, which polarizes light outputted from the semiconductor laser light source to elliptically-polarized light, and which is disposed such that a major axis of the elliptically-polarized light is parallel to a major axis of the laser light. The polarization plate has a phase difference such that a light spot with respect to the elliptical laser light has a circular shape, and the phase difference may be more than 1/4 wavelength and equal to or less than 3/10 wavelength. The polarization plate has a phase difference such that a diameter ratio (minor axis/major axis) of the light spot to the elliptical laser light is equal to or greater than 0.9 and equal to or less than 1.