Abstract: An optical focusing device for focusing an incident optical beam onto a focal plane, as a focal spot. The optical focusing device includes an incident central refractive facet upon which an optical beam impinges, and a high-index glass body through which the incident optical beam passes toward a bottom reflective surface. The bottom reflective surface reflects the optical beam through the body, toward a peripheral reflector. The peripheral reflector focuses the optical beam toward a focal plane on which the focal spot is formed. The focal plane is defined within a pedestal that forms part of the optical focusing device, and that extends from the bottom reflective surface. The central facet is conically shaped for refracting the incident optical beam away from the pedestal, onto the bottom reflective surface.

Abstract: A near-field optical or MO data storage system uses an optical focusing device for focusing an incident optical beam to a small size focal spot. The optical focusing device includes an optically transmissive body which is defined by a generally flat incident surface, a flat, bottom surface disposed opposite and parallel to the incident surface, and a reflective side coated with a reflective layer for reflecting the optical beam through the body toward the bottom surface. The bottom surface defines a focal plane on which the focal spot is formed, for generating a localized evanescent field. The focal spot is located along a central axis P, in very close proximity to the data storage disk, such that the localized evanescent field interacts with the disk, for enabling data to be transduced to and from the disk by effecting near field coupling. An electro-magnetic coil or coil assembly, can optionally be formed on the bottom surface, co-axially with the focal spot, for generating a desired write magnetic field.

Abstract: In a fine-focus actuator, the lens is coupled to a base by extension members. The extension members are rotatably coupled to the base and extend beyond the base. A counter-weight, positioned on the extension members, provides, in the presence of an external inertial force, a torque balancing the torque imposed on the lens holder by the external force. The counter-weight can include elements of the actuator such as magnets, etc.

Abstract: A method and apparatus for recovering information prerecorded in a vertically magnetized magneto-optic recording element wherein a laser is operated in a state of polarization instability (i.e., its TE and TM losses are equal). The linearly polarized (TE and TM) output of the laser is converted to circularly polarized (left-handed and right-handed) polarized radiation, and the latter is used to scan irradiate the recording element. Upon being reflected by the recording element, the circularly polarized radiation is reconverted to linear polarization and fed back to the laser cavity. Depending on which polarization mode (TE or TM) experiences the lesser loss as a result of the MCD effect, the laser operates in either its TE or TM mode. Means are provided for detecting the instantaneous polarization mode of the laser which, in turn, is indicative of the orientation (up/down) of the magnetic domains scanned by the laser radiation.

Abstract: A magneto-optic playback apparatus which plays back information from a recording layer (RL) which exhibits different light absorption of left and right circular polarized beams emitted from a laser (L). The laser (L) operates in two different polarization modes, DE and TM. Polarization converter (PC) converts linear polarized radiation from the laser in one plane to one circular polarization orientation (left or right) in one direction of transmission, and then converts the opposite circular polarized radiation orientation back to linear polarization in the other direction of transmission. The laser switches between modes according to the magnetic orientation of the medium which is determined by the reflected light. Loss control element (LC) selectively increases the TE losses in the extended laser cavity. The self-coupling laser's operation in either the TE or TM mode depends on the differential absorption by the media of right (RCP) or left (LCP) handed circularly polarized beams.