OPTICAL LENS, CONDENSING LENS, OPTICAL PICKUP, AND OPTICAL RECORDING/REPRODUCING DEVICE

摘要

The present invention provides an optical lens having a high refractive index and a low light absorption characteristic in a ultraviolet-wavelength region, a condenser lens fit for the near-field optical recording/reproducing system, an optical pickup capable of dealing with reducing a condensed light spot irradiating a recording medium and making the recording medium higher in density and greater in capacity, and an optical recording/reproducing apparatus comprising the optical pickup to enable optical recording and reproduction in high recording density to be performed. The optical lens 11 is made of optical material selected among HfO₂, HfO₂-Y₂O₃, HfO₂-TiO₂, HfO₂-Sc₂O₃, HfO₂-Nd₂O₃, HfO₂-Ln₂O₃, Sc₂O₃, MgO, Y₂0₃, WO₃, Gd₂O₃, Eu₂O₃, Dy₂O₃. The condenser lens 13 is composed of one or more optical lenses 11, 12 including the optical lens 11. Moreover, in the optical pickup having at least a light source and a condenser lens 13 for converging light emitted from the light source to form a light spot, it is arranged that the light source emits light of wavelengths in the range of 190~450 nm, and the condenser lens 13 includes the optical lens 11. Furthermore, the optical recording/reproducing apparatus is formed to comprise such optical pickup for recording on and reproducing from the recording medium 30.