Abstract: A hologram recording and reproducing device and an angular multiplexing recording and reproducing method capable of detecting an angular error signal for which, in a two-beam angle multiplexing method, high-speed reproducing can be achieved with a superior recovered signal. A branch element branches a light beam, emitted from a light source, into a signal light and a reference light. Angle-variable elements modify the incident angle of the reference light that is incident to the optical information recording medium. A spatial light modulator adds information to the signal light; and an objective lens radiates the signal light to the optical information recording medium. An imaging element detects diffracted light generated from a recording region when the reference light is radiated upon the optical information recording medium; a detection system detects at least two angular error signals for controlling the angle-variable elements; and switching is performed between the two angular error signals.

Abstract: A relatively larger nominal track spacing associated with a first write head is determined and a relatively smaller nominal track spacing associated with a second write head is determined. The first and second write heads simultaneously write to respective different first and second surfaces of a heat-assisted recording medium. A laser write power for a selected one of the first write head and the second write head is changed to enable the first write head and the second write head to operate at an equivalent nominal track spacing.

Abstract: A phase error detector includes a sine wave generation circuit that generates a sine wave signal, based on a first input signal of a first period, a cosine wave generation circuit that generates a cosine wave signal, based on the first input signal, a first calculator that calculates a phase difference between the sine wave signal and a second input signal of a second period, a second calculator that calculates a phase difference between the cosine wave signal and the second input signal, and a first selection unit that outputs the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is within a predetermined range, and outputs a predetermined value having a same sign as a sign of the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is out of the predetermined range.

Abstract: An optical disk device which quickly detects that a transparent disk is loaded is provided. When an optical disk is loaded, a drive controller of an optical disk device drives a spindle motor and checks existence of an optical disk based on a driving result. In addition, the drive controller drives an optical pickup to apply a focus control, to detect whether or not focusing is possible. When it is determined from the driving result that there is an optical disk and that focus is not possible, the drive controller judges that the optical disk (D) is a transparent disk.

Abstract: The disclosed technology provides for a method or system comprising determining size of a super block for a track zone in a storage medium based on at least one parameter of the track zone, wherein the super block includes a super parity for recovery of a failed sector within the super block.

Abstract: An optical disc information device is an optical disc information device for reproducing and/or recording information with respect to an optical disc including a track in the form of a groove, and capable of recording information in a land portion and in a groove portion of the groove. The optical disc information device includes a laser light source, an objective lens, a transmittance limiting element, a dividing element, a light detector, a central amplifier, at least two end amplifiers, a gain controller, an adder, a reproduction signal processor, and a control signal processor. The transmittance limiting element includes a first central region, and at least two first end regions which interpose the first central region therebetween, and attenuates light passing through at least the first end regions out of a light flux emitted from the laser light source more strongly than light passing through the first central region.

Abstract: A heat-assisted magnetic recording (HAMR) write apparatus is coupled with a laser that provides energy. The HAMR write apparatus includes a pole, at least one coil, a waveguide, a near-field transducer (NFT) and at least one antireflective mechanism. The pole writes to a region of the media and includes a media-facing surface. The coil(s) energize the pole. The waveguide is optically coupled with the laser and includes a core and cladding. The waveguide is for directing a portion of the energy toward the NFT, which is located in a transmission direction from the core of the waveguide. The antireflective mechanism(s) are in at least one of a first position in the waveguide, a second position in the NFT and a third position between the waveguide and the NFT.

Abstract: An optical information recording medium has: a recording layer; a super-resolution functional layer; and a protective layer. Letting n be the refractive index of the protective layer with respect to a laser beam focused by a focusing optical system, ?, be the wavelength of the laser beam, and ds be the depth of recording marks, when the super-resolution functional layer is irradiated by the focused laser beam, it forms a focused light spot including central light that irradiates the recording marks and peripheral light that irradiates a region outside the central light. The optical information recording medium further satisfies either the condition that the central light has a positive phase difference with respect to the peripheral light and ds>?/4n, or the condition that the central light has a negative phase difference with respect to the peripheral light and ds<?/4n.

Abstract: Two or more reader sensors are commonly mounted on a read/write head that is configured to read data from a heat-assisted recording medium. For a region of the recording medium, a separation is determined for the reader sensors. A track spacing that provides a target areal density for the region is determined. The track spacing for the region is adjusted to approach a predetermined ratio of the separation.

Abstract: Disclosed herein is an optical disc apparatus capable of reading out information stored in an optical disc medium, the optical disc apparatus including: a light emitting device radiating light; an object lens converging light radiated by the light emitting device on the optical disc medium; and a control section carrying out control to shift the center position of the object lens with respect to the optical-axis position of light radiated by the light emitting device in an operation to read out information from the optical disc medium.

Abstract: A thermally assisted magnetic recording head is disclosed having a spot size converter with at least one secondary waveguide adjoining a top or bottom surface of a primary waveguide. Each waveguide has tapered sides but the secondary waveguide is tapered at a greater angle over a shorter taper distance in order to couple propagated light into the primary waveguide before the front end of the taper. The secondary waveguide terminates in a ridge with a fixed width w3 of about 50-170 nm that is between the front end of the taper and the air bearing surface (ABS). The ridge enables transverse magnetic (TM) transmission mode efficiency above 90% even with a typical process misalignment in the cross-track and height directions. The primary waveguide has a front section with width w2 between an end of its tapered sides and the ABS where w2 is substantially larger than w3.

Abstract: A disk drive is disclosed comprising a disk comprising a plurality of servo sectors defining a plurality of servo tracks. The servo tracks form a plurality of servo zones, where a servo data rate of servo sectors in a first servo zone is different than a servo data rate of servo sectors in a second servo zone. A servo control system servos a head over the disk. An estimated servo state of a servo control system is generated, and when the head crosses from a first servo zone to a second servo zone, the estimated servo state is adjusted to compensate for a transient in a circumferential distance between a servo sector in the first servo zone and a servo sector in the second servo zone.

Abstract: The present invention provides a printed coil substrate for an optical disc actuator so that the sensitivity will change as little as possible when shifting in a focal direction and a tracking direction. Although the coil patterns laminated at a corresponding position have approximately same shape, center locations in shape of the tracking coil and the focus coils are displaced between the neighboring substrate layers, and the center locations in shape are displaced by a predetermined distance toward a direction of driving the movable portion driven by the coils. Even when the coil pattern of the first layer is moved in a direction of leaving from the position where magnetic force of the magnet is strong, the coil pattern of the second layer is simultaneously moved into the position where magnetic force of the magnet is strong. Therefore, the change of the sensitivity can be relatively compensated.

Abstract: A method for writing data onto a medium on which data are stored in tracks includes encoding the data into at least one codeword, and writing a respective portion of each of the at least one codeword onto respective different tracks on the medium. The writing may include writing a respective portion of each of the at least one codeword onto respective different adjacent tracks on the medium. Another method for reading data includes positioning a plurality of read heads to read codewords that have been written across multiple tracks of a medium. Each read head in the plurality of read heads reads a different portion of the first group of the multiple tracks, and where each different portion of the multiple tracks overlaps at least one other different portion of the multiple tracks. Signals are detected from the plurality of read heads, and the detected signals are decoded.

Abstract: According to one embodiment, a magnetic medium includes a plasmonic underlayer having an Au alloy, where the Au alloy includes one or more alloying components that are substantially immiscible in Au; and a magnetic recording layer above the plasmonic underlayer. According to another embodiment, a magnetic medium, includes a multilayered plasmonic underlayer; and a magnetic recording layer above the multilayered plasmonic underlayer.

Abstract: A method of testing a TAMH includes providing a slider body having a waveguide embedded therein with an incidence end extending toward a back surface of the slider body; providing a light source unit including a light source and a unit substrate; coating a bonding material layer on the back surface, under the bottom, or both on the back surface and under the bottom of the unit substrate; coating a localization material layer on the back surface; aligning the light source unit to the slider body; causing a light emitted from the light source and allowed to be incident on the incidence end to anneal the localization material layer to generate an annealing mark; removing the light source unit or the light source from the slider body; and measuring a position offset between the annealing mark and the incidence end. The method can evaluate alignment accuracy of a slider body and a light source unit in two dimensional directions.

Abstract: A mark having a length nT (n being an integer equal to or greater than 3 and T being a clock period) is formed by modulating irradiation laser power with three values of recording power Pw, erase power Pe, and bias power Pb (Pw>Pe>Pb). Constant strength periods (At) of the recording power Pw are set as AtT, A1T, . . . , and AmT and constant strength periods (Bt) of the bias power Pb are set as BtT, B1T, . . . , BmT, and CT (C=?1 to 3). The application of laser is divided into pulses in order of AtT, BtT, A1T, B1T, . . . , AmT, BmT, and CT (m=(n?k)/2, k=3 (if n is an odd number), or k=4 (if n is an even number)). (Here, the constant strength period of the recording power Pw for n=3, n=4, n?5 (odd number), and n?6 (even number) is set as At3, At4, Atod, and Atev, the constant strength period of the bias power Pb for n=3, n=4, n?5 (odd number), and n?6 (even number) is set as Bt3, Bt4, Btod, and Btev, and then, At3+Bt3=Atod+Btod=Am+Bm=2T and At4+Bt4=Atev+Btev=3T).

Abstract: Provided are an optical information recording/reproduction device and an optical information recording/reproduction method with which retry data during verify error detection can be efficiently recorded. In the optical information recording/reproduction device for recording data on an optical information recording media and reproducing data from an optical information recording medium, if verify error data is detected at a first cure unit region on the optical information recording medium, verify error retry data is recorded at a second cure unit region which is different to the first cure unit region.

Abstract: An apparatus, method, and computer readable medium for writing data on a highly indestructible material is disclosed. A laser may write data on a first side of a highly indestructible material. The data may then be marked as non-rewriteable. The data may also be written on a second side of the highly indestructible material, with the second side being opposite the first side. The highly indestructible material may comprise a stainless steel storage medium.

Abstract: Appropriate recording with respect to a hologram recording medium is to be realized. After a region recording process of arranging holograms in which information is recorded at a predetermined interval in a first predetermined region of the hologram recording medium, and before a post-curing with respect to the first predetermined region is performed, signal light and reference light are applied onto a region different from the first predetermined region to perform information recording.