Optical disk drive

An optical disk drive comprising:

• two optical disks which transmits laser beams, disposed at upper and lower positions;
• a first laser beam irradiation mechanism disposed on the upper surface side of the optical disk at the upper position, and used for recording or reproducing information on the lower surface of the optical disk at the lower position;
• a first evanescent optical system configured to receive the first laser beam irradiated from the first laser beam irradiation mechanism, passing through the two optical disks, and configured to irradiate the evanescent beam to the lower surface of the optical disk at the lower position;
• a second laser beam irradiation mechanism disposed on the lower surface side of the optical disk at the lower position, and used for recording or reproducing information on the upper surface of the optical disk held at the lower position;
• a second evanescent optical system configured to receive the second laser beam irradiated from the second laser beam irradiation mechanism, passing through the optical disk at the lower position, and configured to radiate the second evanescent beam to the upper surface of the optical disk held at the lower position;
• a third laser beam irradiation mechanism disposed on the upper surface side of the optical disk at the upper position, and used for recording or reproducing information on the lower surface of the optical disk at the upper position;
• a third evanescent optical system configured to receive the third laser beam irradiated from the third laser beam irradiation mechanism, passing through the optical disk at the upper position, and configured to radiate the third evanescent beam to the lower surface of the optical disk at the upper position;
• a fourth laser beam irradiation mechanism disposed on the lower surface side of the optical disk at the lower position, and used for recording or reproducing information on the upper surface of the optical disk at the upper position;
• and
• a fourth evanescent optical system configured to receive the fourth laser beam irradiated from the fourth laser beam irradiation mechanism, passing through the two optical disks, and configured to irradiate the fourth evanescent beams to the upper surface of the optical disk at the upper position.