| 摘要 |
PURPOSE:To stably obtain super-high resolution phenomena against the distortion of light intensity distribution due to a disk inclination and aberrations without using a slit plate for removing the side-robe component of a light beam. CONSTITUTION:An optical pickup is provided with a light shielding plate 4 for attenuating the light intensity of the center part of a light beam emitting from a laser bean source 2, an objective lens 6 converging the light beam on an optical disk as a minute spot and a condenser lens 8 converging the reflected light from the optical disk 20 and introducing the light to a photodetector 12. On the converging position on the optical path between the objective lens 6 and the photodetector 12, a mask plate 9 composed of a third order nonlinear optical material and having an optical characteristic so as to increase the transmissivity with the increase of light intensity is provided. |
