A method includes generating, during manufacture of a heat-assisted magnetic recording (HAMR) disk drive, a temperature compensation equation for a compensation factor using initial operating currents supplied to a laser diode of the disk drive at different initial operating temperatures and an efficiency value based on the initial operating temperatures. The operating currents are representative of currents for recording data to or erasing data from a magnetic recording medium. The temperature compensation equation is stored in the disk drive. A subsequent efficiency value is determined based on at least one of the initial operating temperatures and an operating temperature differing from the initial operating temperatures. An updated compensation factor at the operating temperature is determined during field operation using the temperature compensation equation and the subsequent efficiency value. An updated operating current is calculated using the updated compensation factor and the operating temperature. A current supplied to the laser diode for a subsequent write operation is adjusted to the updated operating current.

A method includes generating, during manufacture of a heat-assisted magnetic recording (HAMR) disk drive, a temperature compensation equation for a compensation factor using initial operating currents supplied to a laser diode of the disk drive at different initial operating temperatures and an efficiency value based on the initial operating temperatures. The operating currents are representative of currents for recording data to or erasing data from a magnetic recording medium. The temperature compensation equation is stored in the disk drive. A subsequent efficiency value is determined based on at least one of the initial operating temperatures and an operating temperature differing from the initial operating temperatures. An updated compensation factor at the operating temperature is determined during field operation using the temperature compensation equation and the subsequent efficiency value. An updated operating current is calculated using the updated compensation factor and the operating temperature. A current supplied to the laser diode for a subsequent write operation is adjusted to the updated operating current.

A method includes generating, during manufacture of a heat-assisted magnetic recording (HAMR) disk drive, a temperature compensation equation for a compensation factor using initial operating currents supplied to a laser diode of the disk drive at different initial operating temperatures and an efficiency value based on the initial operating temperatures. The operating currents are representative of currents for recording data to or erasing data from a magnetic recording medium. The temperature compensation equation is stored in the disk drive. A subsequent efficiency value is determined based on at least one of the initial operating temperatures and an operating temperature differing from the initial operating temperatures. An updated compensation factor at the operating temperature is determined during field operation using the temperature compensation equation and the subsequent efficiency value. An updated operating current is calculated using the updated compensation factor and the operating temperature. A current supplied to the laser diode for a subsequent write operation is adjusted to the updated operating current.

A frequency data transmission and encryption system comprises a transceiver module. The transceiver module is configured to receive and transmit computer-readable instructions via transmission signals comprising two distinct signals having a first frequency and a second frequency different than the first frequency. The transceiver module is further configured to convert the two distinct signals to and from a first set of computer-readable instructions based on the first frequency using a first conversion method, and a second set of computer-readable instructions based on the second frequency using a second conversion method different from the first conversion method.

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 frequency data transmission and encryption system comprises a transceiver module. The transceiver module is configured to receive and transmit computer-readable instructions via transmission signals comprising two distinct signals having a first frequency and a second frequency different than the first frequency. The transceiver module is further configured to convert the two distinct signals to and from a first set of computer-readable instructions based on the first frequency using a first conversion method, and a second set of computer-readable instructions based on the second frequency using a second conversion method different from the first conversion method.

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.

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.