Abstract: The present invention relates to an information storage medium and an optical device for reproducing information recorded in the information storage medium. In the information storage medium, the initial phase of any cell in the information layer is a crystal phase or an amorphous phase, and either of the two phases is changed into the other phase by electronic heating. Since reflectivity to incident light is different in accordance with phase of the cell, information recorded on the medium may be reproduced by using the above property.

Abstract: An apparatus capable of tracking a sample surface level in a z direction and oscillating a cantilever at resonant frequency by using a frequency separation scheme in non-contact mode and method thereof. The inventive apparatus includes a sensing unit for sensing a sample surface; a frequency transforming unit for transforming the sensed signal; a frequency combining unit for combining signals; and an actuating unit for actuating the sensing unit.

Abstract: A micro-integrated probe type head and an optical recording system using the same for recording/reading-out high-density optical information in a near field recording (NFR) manner are provided. The provided micro-integrated probe type head and the optical recording system using the same use a concept of a head that records/reproduces the information by focusing a beam to a probe through a wave guide, a microlens, and a micro-mirror, and by detecting a reflected beam. In this case, the probe is formed by a silicon process to have an aperture with a size of tens of nanometers. By driving the head in a disk actuation structure, high-density near-field optical information having a recording size of 50 to 100 nm is recorded/reproduced at a high speed in a manner of possibly using a conventional tracking technology of an optical disk drive (ODD) or a hard disk drive (HDD).