An optical pickup includes a light source 1; a diffraction element 2 for generating a write main beam and a read sub-beam via diffraction; an objective lens 5; a wavelength plate 9; a polarization hologram element 7 having a plurality of diffraction regions with different diffraction characteristics, designed so that each diffraction region separates a light beam reflected from the optical storage medium and transmitted through the wavelength plate into a 0th order light beam and ±1st order light beams; an actuator 11; and a photodetector 10 configured to detect a light beam reflected from the optical storage medium 6 and diffracted by the polarization hologram element 7. The photodetector 10 generates an RF signal from a detection result concerning a 0th order light beam derived from the main beam, generates a focus error signal and a tracking error signal from a detection result concerning one of ±1st order light beams derived from the main beam, and generates a signal indicating that data has been recorded normally from a detection result concerning a 0th order light beam derived from the sub-beam.