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

An apparatus comprises a laser diode configured to generate light during a write operation. A slider comprises a near-field transducer (NFT) and an optical waveguide. The slider is configured for heat-assisted magnetic recording and to communicate the light to the NFT via the waveguide. A writer heater of the slider is configured to receive power during the write operation. A thermal sensor is situated at or near an air bearing surface of the slider. The thermal sensor is configured to produce a sensor signal in response to sensing back-heating from the medium while the NFT generates heat during a write operation. Circuitry, coupled to the thermal sensor, is configured to compare the sensor signal to a threshold and generate an output signal indicative of degradation of NFT performance in response to the sensor signal exceeding the threshold.

An apparatus comprises a laser diode configured to generate light during a write operation. A slider comprises a near-field transducer (NFT) and an optical waveguide. The slider is configured for heat-assisted magnetic recording and to communicate the light to the NFT via the waveguide. A writer heater of the slider is configured to receive power during the write operation. A thermal sensor is situated at or near an air bearing surface of the slider. The thermal sensor is configured to produce a sensor signal in response to sensing back-heating from the medium while the NFT generates heat during a write operation. Circuitry, coupled to the thermal sensor, is configured to compare the sensor signal to a threshold and generate an output signal indicative of degradation of NFT performance in response to the sensor signal exceeding the threshold.

A first waveguide portion receives light from an energy source in a fundamental transverse electric (TE.sub.00) mode. A mode converter converts a portion of the light to higher-order transverse electric (TE.sub.10) mode. A second waveguide portion receives the light at the TE.sub.10 mode and delivers the light to a near-field transducer that heats a recording medium in response thereto. An optical spatial mode filter prevents remnant light in the TE.sub.00 mode from affecting the recording medium while passing the light at the TE.sub.10 mode.

A recording medium recording a magnetic material simulation program includes: acquiring a shape model including element regions of a shape of a core, property information indicating physical properties of a magnetic material of the core, and coil current information indicating a time change in a current through a coil around the core; specifying a first current density of the coil at a first time, based on the coil current information; computing, using the property information and the first current density, first index values at the first time for positions in the shape model; computing, using the first index values, a charge density of each element region; specifying a second current density of the coil at a second time, based on the coil current information; and computing, using the property information, the second current density, and the charge density, second index values at the second time for the positions.

Data is written to a recording medium via a read/write head. Subsequent to the writing, the data is read via a read transducer of a read/write head. An instability indicator is derived based on measurements performed while the reading the data. If the instability indicator exceeds a threshold, a current applied to a write coil of the read/write head is changed for subsequent write operations.

Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position a selected head among one or more heads proximate to a corresponding disk surface among the one or more disks; and one or more processing devices. The one or more processing devices are configured to generate a map of laser mode hop effects across the corresponding disk surface, for the selected head. The one or more processing devices are further configured to apply a laser mode hop mitigation in operating the selected head, based on the map of laser mode hop effects.

A fan-less Multiprocessor-Computing-Apparatus (MCA) housed in a Metallic-Enclosure (ME) acting as an electromagnetic-Shield for wireless-communications/interconnects (WLI) among components of MCA enabling the whole-range-frequencies from lows of 10-HZs to highs of GHZ and beyond to be able to address almost unlimited Shared-Memory-Units (SMUs) by each processor with each SMU permanently tuned to send/receive data at a particular frequency. The ME is dust-proofed and filled with clean-air/vacuum for efficient-and-reliable WLI. The ME also acts as a heat-sink with the components of MCA placed on Circuit-Boards are mounted on inside in a plane parallel to the respective side of the ME of any required size and shape and heat producing components are firmly attached to the ME, which is waterproofed and placed-under-water for cooling. The SMUs are made up of static non-volatile Random Access Memory that can be read-from and written-to optically.

A thermal assisted magnetic recording head executing magnetic recording while locally heating a magnetic recording medium includes a plasmon generator generating surface plasmon and generating near-field light from the surface plasmon at an end surface situated on an air bearing surface facing the magnetic recording medium, a main pole being in contact with the plasmon generator and exposed on the air bearing surface, a metal protective layer situated on an opposite side to the plasmon generator when viewed from the main pole and positioned to overlap with a part of the main pole when viewed from one side in a down track direction, and an overcoat protective layer covering the metal protective layer. The overcoat protective layer is formed on a flat surface at least at a position where it overlaps with the main pole when viewed from one side in the down track direction, and the metal protective layer configures a part of the flat surface. Moreover, the overcoat protective layer has a flat bottom surface at least at a position where it overlaps with the main pole when viewed from one side in the down track direction.

A waveguide that includes a first cladding layer, the first cladding layer having an index of refraction, n.sub.3; a gradient index layer positioned adjacent the first cladding layer; an assist layer positioned adjacent the gradient index layer, the assist layer having an index of refraction, n.sub.2; a core layer positioned adjacent the assist layer, the core layer having an index of refraction, n.sub.1; and a second cladding layer, the second cladding layer having an index of refraction, n.sub.4, wherein n.sub.1 is greater than n.sub.2, n.sub.3, and n.sub.4; and n.sub.2 is greater than n.sub.3 and n.sub.4.