Read Rite Corporation

Chuan He

Hong M Chen

Charles C Cheng

Joseph J Miceli, Jr

Ross W Stovall

Carl J Carlson

Yugang Wang

Charles C K Cheng

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. The peripheral reflector surrounds the central facet and can have various appropriate shapes, such as an aspherical shape or a tilted parabolic shape, which compensates for the conical factor and aberrations introduced by the central facet. The top surface includes the central facet and the peripheral facet, and can be made substantially flat using diffractive optical elements or Fresnel optics.

High numerical aperture optical focusing device having a conical incident facet and a parabolic reflector for use in data storage systems

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. The peripheral reflector surrounds the central facet and can have various appropriate shapes, such as an aspherical shape or a tilted parabolic shape, which compensates for the conical factor and aberrations introduced by the central facet. The top surface includes the central facet and the peripheral facet, and can be made substantially flat using diffractive optical elements or Fresnel optics. The focal spot of the optical rays can be optimized using sequential quadratic program and a set of optimized coefficients.

High numerical aperture optical focusing device for use in data storage systems

A magneto-optical head using a catadioptric focusing device comprised of an incident surface, a bottom reflective surface, a pedestal, and a body. The incident surface is generally flat and is comprised of a central diffractive, optically transmissive facet and a peripheral facet comprised of a kinoform phase profile. In a data writing or reading mode, an incident optical beam, such as a laser beam impinges upon the central facet, and is diffracted thereby. The incident laser beam can be collimated, convergent or divergent. The laser beam passes through the transparent body, and impinges upon the bottom reflective surface. The laser beam is then reflected by the bottom reflective surface, through the body, unto the kinoform phase profile. The laser beam is reflected and refracted by the peripheral kinoform phase profile as a focused beam, through the body, and is focused as a focal point. The focal point is preferably located at, or in close proximity to a pedestal edge, along a central axis, in very close proximity to the disk. This will allow the focused optical beam to propagate toward, or penetrate the disk through evanescent wave coupling, for enabling the transduction of data to and from the disk.

High NA solid catadioptric focusing device having a flat kinoform phase profile

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. The reflective side of the optical focusing device preferably has a parabola shaped curvature, but other shapes can alternatively be selected. For example, the side curvature can have a tilted parabola shape.

A near-field optical or magneto-optical 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 objective lens, an optically transparent base plate, and an optically transparent adapter. The adapter is secured to, and disposed intermediate the objective lens and the base plate, and includes an opening that faces the base plate. A fluid fills the adapter opening to form a fluid cell when the adapter is secured to the base plate. The fluid has an index of refraction that substantially matches the index of refraction of the base plate.

The method of making and self-aligning a magneto-optical head at a wafer level is as follows: A flat optical substrate is molded or heat pressed in batches as a wafer level to form the desired lens shapes. Coil cavities or depressions are simultaneously formed with the lens to accommodate the coil assembly. Conductive plugs are formed in proximity to the cutting lines, for wire bonding attachment to the coil. The plugs are filled with a conductive material such as copper. The plugs do not extend through the entire depth of the optical wafer, thus further facilitating the mass production of the integrated heads. The slider body wafer is formed from silicon or other appropriate material. The slider body wafer and the lens/coil wafer are bonded. Coils and pedestals are formed on the lens / coil plate using thin-film processing techniques. Reflective surfaces are deposited on the bottom surface of the substrate, opposite the lens. The mirror material around the pedestal areas and plugs is masked and removed. An alumina layer is then deposited to define the air bearing surface and the pedestal. Yokes are then formed by means of lithography and plating in the base and sides of the depressions to assume a desired shape. A series of alternating insulating layers and conductive coil layers is formed. A protective layer seals the coil assembly, and is lapped to correct the lens thickness and to provide proper focal plane.

Near field magneto-optical head made using wafer processing techniques

A method of making and self-aligning a disk data storage read/write head that uses a catadioptric focusing device (or lens) having a high numerical aperture (NA), which does not introduce significant spot aberration on a storage medium. The manufacturing process of the head is carried out at a wafer level, and is facilitated significantly by the flatness of the focusing device. An exemplary manufacturing process is implemented as follows: A lens coil/plate is formed by molding a flat optical substrate to form the desired lens shapes. Coil cavities or depressions are formed simultaneously with the lens to accommodate a coil. Conductive plugs are formed in proximity to cutting lines for wire bonding attachment to the coil. A slider wafer is formed and bonded to the lens/coil wafer. Coils and pedestals are also formed on the lens/coil plate using thin-film processing techniques, and reflective surfaces are deposited on the bottom surface of the substrate, opposite the lens. The focusing device includes an incident surface, a reflective surface, a focal pedestal, and a body. The incident surface is generally flat and is comprised of a central diffractive, optically transmissive surface and a peripheral reflector. The peripheral reflector is comprised of a reflective-diffractive surface, or alternatively, a reflective-kinoform phase profile.

Wafer processing techniques for near field magneto-optical head

A magneto-optical head using a catadioptric focusing device comprised of an incident surface, a bottom reflective surface, a pedestal, and a body. The incident surface is generally flat and is comprised of a central diffractive, optically transmissive facet and a peripheral facet comprised of a diffractive-reflective surface or facet. In a data writing or reading mode, an incident optical beam, such as a laser beam impinges upon the central facet, and is diffracted thereby. The incident laser beam can be collimated, convergent or divergent. The laser beam passes through the transparent body, and impinges upon the bottom reflective surface. The laser beam is then reflected by the bottom reflective surface, through the body, unto the peripheral diffractive-reflective surface. The laser beam is reflected and also diffracted by the peripheral diffractive-reflective surface as a focused beam, through the body, and is focused as a focal point located at, or in close proximity to a pedestal edge, along a central axis, in very close proximity to the disk. This will allow the focused optical beam to propagate toward, or penetrate the disk through evanescent wave coupling, for enabling the transduction of data to and from the disk.

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Fremont, CA, United States of America

Chuan He