International Business Machines Corporation

Matthias C Krantz

LeRoy D Dickson

Andrew Ching Tam

Timothy C O'Sullivan

Vlad J Novotny

Richard A Bargerhuff

An optical data storage system comprises a laser for generating a beam of light, an optical data storage media, transmission optics for directing the beam of light to the optical medium, reception optics for receiving a reflected beam from the medium, and circuits for generating a data, tracking error and focus error signals. The reception optics includes a segmented detector. The signals from at least two of these segments are differentially adjusted such that the resulting output focus error signal is approximately independent of nonfocus wavefront aberrations.

Optical data storage system with aberration compensation for reduced

Slider disk stiction is reduced in a disk-based storage device by providing one or more step projections on the air bearing surface of a slider. The rear part of the step projections which rest on the disk surface projections are forward of the slider pivot point. When the slider rests on a disk surface, the step projections elevate the leading edge of the slider, which imposes a static pitch angle on the slider, reducing the slider/disk contact area. Provision is also made for contouring the slider air bearing surface adjacent to the slider leading edge, using a taper or the step projection leading face, to compress the airflow and provide a stable slider air bearing during disk file operation.

Step projection air bearing slider with improved stiction performance

A hologram system comprises two volume holograms on two separate substrates which are cemented together with an optical cement. The two volume holograms are manufactured with identical Bragg planes. The two volume holograms are oriented with respect to one another such that the Bragg planes are optically aligned. The result is that the two volume holograms operate as a single thicker volume hologram wherein the Bragg angle sensitivity is greatly increased.

Increased Bragg angle sensitivity hologram system and method

A hologram element receives a first and second laser beams at a first angle relative to one another. The hologram element emits the laser beams at a second angle relative to one another. The second angle is less than the first angle. The result is that laser beams from widely divergent laser sources may be directed into the same optical channel. Closely spaced beams are thereby provided for multiple beam optical data storage systems.

Hologram element system

An optical data storage system having a highly integrated optical storage head that (1) integrates the read, write and servo paths, (2) comprises a monolithic laser-detector storage array that is integrated on a single chip an, wherein laser-detector alignment desirably is fixed at the time of fabrication, and (3) comprises a four-hologram optical element that directs light to an optical disk and divides the returning light into one track error and two focus error servo beams and two polarization component beams for data detection, and also provides a satellite beam of the incident laser beam for monitoring power of the laser beam.

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San Jose, CA, United States of America

Matthias C Krantz