Various illustrative aspects are directed to a data storage device, comprising: one or more disks; an actuator assembly comprising a head, and configured to position the head over a corresponding disk surfaces; and one or more processing devices, wherein the head comprises: a write element; a laser unit; and a fly height control element, and wherein the one or more processing devices are configured to: iteratively perform write start operations of write start patterns with the head on the corresponding disk surface, at a plurality of values of at least one of laser pre-bias current, and write backoff; detect pattern signal amplitudes of the write start patterns on the corresponding disk surface; and determine a relation of write backoff to laser pre-bias current for the head, based at least in part on the pattern signal amplitudes.

It is possible to provide a new information recording/reproduction method and a device which can realize a small-size large-capacity memory having a characteristic equivalent to or higher than a hologram memory. The optical information recording/reproduction device includes: recording light generator (51) which generates a recording light (55) in a polarization state having two mutually orthogonal polarization components with a phase difference at an arbitrary polarization base; reproduction light generator (61) which generates a reproduction light (65) in a polarization state having only a single polarization component at a arbitrary polarization basis; recording medium (71) in which optical information is recorded by recording light (55) and the recorded optical information is reproduced by reproduction light; and optical information detector (polarimeter 81) which retrieves information light (72) after being applied to recording medium (71) and detects the light as optical information. Provided is also an optical information recording/reproduction method using the device.

Disclosed is an optical disk drive for wireless power transmission. The optical disk drive in an embodiment of the present invention comprises a tray on which a optical disk is to be seated; a driving unit for rotating the optical disk to be seated on the tray and reading or writing the optical disk; a wireless power transmitting module to be seated on the tray and comprising a primary coil and a transmitting circuit unit; a power supply unit for supplying power; and a controller for controlling the power supply unit to supply power to the wireless power transmitting module when determining that the wireless power transmitting module is seated on the tray.

Disclosed is an optical disk drive for wireless power transmission. The optical disk drive in an embodiment of the present invention comprises a tray on which a optical disk is to be seated; a driving unit for rotating the optical disk to be seated on the tray and reading or writing the optical disk; a wireless power transmitting module to be seated on the tray and comprising a primary coil and a transmitting circuit unit; a power supply unit for supplying power; and a controller for controlling the power supply unit to supply power to the wireless power transmitting module when determining that the wireless power transmitting module is seated on the tray.

A recording head includes a waveguide configured to deliver light from a light source to a media-facing surface of the recording head. A near-field transducer is at the media-facing surface the proximate the waveguide. The near-field transducer includes a plasmonic structure with at least two opposing internal surfaces. A dielectric material fills a region between the at least two opposing internal surfaces. A dielectric slit extends between the at least two opposing internal surfaces. The dielectric slit is substantially parallel to the media-facing surface and includes a transparent material with a refractive index different than that of the dielectric material.

Disclosed is an optical disk drive for wireless power transmission. The optical disk drive in an embodiment of the present invention comprises a tray on which a optical disk is to be seated; a driving unit for rotating the optical disk to be seated on the tray and reading or writing the optical disk; a wireless power transmitting module to be seated on the tray and comprising a primary coil and a transmitting circuit unit; a power supply unit for supplying power; and a controller for controlling the power supply unit to supply power to the wireless power transmitting module when determining that the wireless power transmitting module is seated on the tray

A method is provided for judging whether a double-sided optical disc is placed reversely. Firstly, the disc is loaded. Then, a first optical pickup head emits a first laser beam to a first specified area of the disc and receives a first reflected laser beam. A second optical pickup head emits a second laser beam to a second specified area of the disc and receives a second reflected laser beam. If the first reflected laser beam generates an alternate brightness and darkness change and the second reflected laser beam does not generate the alternate brightness and darkness change, the disc is not placed reversely. If the first reflected laser beam does not generate the alternate brightness and darkness change and the second reflected laser beam generates the alternate brightness and darkness change, the disc is placed reversely.

A method is provided for judging whether a double-sided optical disc is placed reversely. Firstly, the disc is loaded. Then, a first optical pickup head emits a first laser beam to a first specified area of the disc and receives a first reflected laser beam. A second optical pickup head emits a second laser beam to a second specified area of the disc and receives a second reflected laser beam. If the first reflected laser beam generates an alternate brightness and darkness change and the second reflected laser beam does not generate the alternate brightness and darkness change, the disc is not placed reversely. If the first reflected laser beam does not generate the alternate brightness and darkness change and the second reflected laser beam generates the alternate brightness and darkness change, the disc is placed reversely.

A method is provided for judging whether a double-sided optical disc is placed reversely into an optical disc drive. The optical disc drive includes a first control module and a second control module. The first control module includes a first optical pickup head. The second control module includes a second optical pickup head. Firstly, the double-sided optical disc is loaded. Then, the first optical pickup head of the first control module emits a laser beam to a specified area of the double-sided optical disc and receives a reflected laser beam from the specified area. If the reflected laser beam generates an alternate brightness and darkness change, the double-sided optical disc is not placed reversely. If the reflected laser beam does not generate the alternate brightness and darkness change, the double-sided optical disc is placed reversely.

A method is provided for judging whether a double-sided optical disc is placed reversely into an optical disc drive. The optical disc drive includes a first control module and a second control module. The first control module includes a first optical pickup head. The second control module includes a second optical pickup head. Firstly, the double-sided optical disc is loaded. Then, the first optical pickup head of the first control module emits a laser beam to a specified area of the double-sided optical disc and receives a reflected laser beam from the specified area. If the reflected laser beam generates an alternate brightness and darkness change, the double-sided optical disc is not placed reversely. If the reflected laser beam does not generate the alternate brightness and darkness change, the double-sided optical disc is placed reversely.