A storage medium controller has been designed to maintain thermal stability of a heat source based on a history of heat source active/inactive durations so that a variation in spot size generated by the heat source is reduced during Heat Assisted Magnetic Recording (HAMR). The storage medium controller modulates power to the heat source based on these active/inactive durations. While the heat source is inactive, the storage medium controller increases a thermal compensation value and after the heat source is activated, the storage medium controller drives the heat source according to a current parameter proportional to the thermal compensation value. As the heat source continues being active, the storage medium controller decreases the thermal compensation value and proportional current parameter so that thermal stability of the heat source is maintained.

A storage medium controller has been designed to maintain thermal stability of a heat source based on a history of heat source active/inactive durations so that a variation in spot size generated by the heat source is reduced during Heat Assisted Magnetic Recording (HAMR). The storage medium controller modulates power to the heat source based on these active/inactive durations. While the heat source is inactive, the storage medium controller increases a thermal compensation value and after the heat source is activated, the storage medium controller drives the heat source according to a current parameter proportional to the thermal compensation value. As the heat source continues being active, the storage medium controller decreases the thermal compensation value and proportional current parameter so that thermal stability of the heat source is maintained.

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.

According to one embodiment, a magnetic recording apparatus measures and stores recording signal quality of a disk at an initial stage, inspects the recording signal quality before data is recorded, determines whether or not the recording signal quality obtained in the inspection satisfies a standard when compared to the stored recording signal quality at the initial stage, adjusts, based on a result of the determination, light irradiation power of a light irradiation element so as to satisfy the standard, determines a read offset amount based on a result of the adjustment, and performs control so that a position of a read head is shifted based on the determined read offset amount.

A heat-assisted recording head is moved onto a ramp such that the recording head is thermally isolated from a moving disk. A heating device is activated on the recording head to cause the recording head to obtain a high temperature that is not obtainable when proximate to the moving disk. The recording head is moved over the moving disk such that the recording head reaches an operating temperature that is below the high temperature. One or more temperatures between the high temperature and the operational temperature are determined at which a laser of the recording head experiences mode-hopping. The one or more temperatures are stored and accessed by a controller to mitigate mode hopes during an operation of the recording head.

A heat-assisted recording head is moved onto a ramp such that the recording head is thermally isolated from a moving disk. A heating device is activated on the recording head to cause the recording head to obtain a high temperature that is not obtainable when proximate to the moving disk. The recording head is moved over the moving disk such that the recording head reaches an operating temperature that is below the high temperature. One or more temperatures between the high temperature and the operational temperature are determined at which a laser of the recording head experiences mode-hopping. The one or more temperatures are stored and accessed by a controller to mitigate mode hopes during an operation of the recording head.

A method includes writing first data to a first track of a magnetic recording medium of a storage device. First parity sectors corresponding to the first data are written. The first parity sectors have a first size. Second parity sectors corresponding to the first data are written. The second parity sectors have a second size. Second data is written to a second track of the magnetic recording medium. The second track is adjacent to the first track. It is determined whether an unrecoverable data error has occurred on the second track. After writing to the second track and determining that no unrecoverable data error has occurred, the first and second parity sectors corresponding to the first data are released.

An apparatus includes a substrate. A laser is formed on a non-self supporting structure and bonded to the substrate. A waveguide is deposited proximate the laser. The waveguide is configured to communicate light from the laser to a near-field transducer that directs energy resulting from plasmonic excitation to a recording medium. A light detector is configured to detect an amount of light. At least one laser heater is disposed proximate the laser. A controller is configured to control current supplied to the at least one heater based on the detected amount of light.

A storage medium controller has been designed to maintain thermal stability of a heat source based on a history of heat source active/inactive durations so that a variation in spot size generated by the heat source is reduced during Heat Assisted Magnetic Recording (HAMR). The storage medium controller modulates power to the heat source based on these active/inactive durations. While the heat source is inactive, the storage medium controller increases a thermal compensation value and after the heat source is activated, the storage medium controller drives the heat source according to a current parameter proportional to the thermal compensation value. As the heat source continues being active, the storage medium controller decreases the thermal compensation value and proportional current parameter so that thermal stability of the heat source is maintained.

A storage medium controller has been designed to maintain thermal stability of a heat source based on a history of heat source active/inactive durations so that a variation in spot size generated by the heat source is reduced during Heat Assisted Magnetic Recording (HAMR). The storage medium controller modulates power to the heat source based on these active/inactive durations. While the heat source is inactive, the storage medium controller increases a thermal compensation value and after the heat source is activated, the storage medium controller drives the heat source according to a current parameter proportional to the thermal compensation value. As the heat source continues being active, the storage medium controller decreases the thermal compensation value and proportional current parameter so that thermal stability of the heat source is maintained.