A slider configured for heat-assisted magnetic recording comprises a magnetic writer, a near-field transducer, and an optical waveguide coupling the near-field transducer to a light source. The writer is situated proximate the near-field transducer at an air bearing surface of the slider and comprises a first return pole, a second return pole, and a write pole situated between and spaced apart from the first return pole and the second return pole. A structural element is situated at or near the air bearing surface between the write pole and one of the first and second return poles. The structural element comprises a cavity. A thermal sensor is disposed in the cavity. The thermal sensor is configured for sensing contact between the slider and a magnetic recording medium, asperities of the medium, and output optical power of the light source.

An apparatus includes a first waveguide core extending along a light-propagation direction and configured to receive light from a light source at a combined transverse electric (TE) mode and a transverse magnetic (TM) mode. A second waveguide core is spaced apart from the first waveguide core and is configured to couple light at a TM mode to the second waveguide core. A near-field transducer (NFT) is disposed at a media-facing surface of a write head, the NFT receiving the light from the first waveguide core or the second waveguide core and heating a magnetic recording medium in response thereto.

A slider for heat assisted magnetic recording (HAMR) is provided. The slider includes a writer for writing data to a HAMR medium, a reader for reading data stored on the HAMR medium, a near field transducer (NFT), a first waveguide optically coupled to the NFT, a slider laser configured to generate and transmit a first light energy to the first waveguide such that the NFT causes a portion of the HAMR medium to heat up, to assist the writer for writing data to the HAMR medium, and a second waveguide optically coupled to the NFT, for transmitting a light energy from an external laser to the NFT to optically anneal the NFT during a fabrication process of the slider.

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.

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.

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.

The present disclosure relates to pretreating a magnetic recording head. For a HAMR head, a NFT is present. Current can be applied to the NFT to condition the NFT. The current is applied in one of three ways: slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over a predetermined period of time, applying the current at a fixed value below the optical laser current for the predetermined period of time, or slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over the predetermined period of time while also intermittently removing the current. By conditioning the NFT in such a manner, the HAMR head can avoid thermal shock and thermal fatigue and thus increase the lifetime of the magnetic media drive.

A peak location calculation device includes a peak value detection block that detects a plurality of candidates for a peak value of intensity of laser light received by an imaging unit consisting of an imaging element formed of a plurality of pixels, and a peak location calculation block that calculates an approximation function that approximates an intensity distribution of the laser light using the plurality of candidates for peak values detected by the peak value detection block. The peak location calculation block calculates the approximation function that minimizes an error between intensity values of the plurality of candidates for the peak value and values of the approximation function.

A peak location calculation device includes a peak value detection block that detects a plurality of candidates for a peak value of intensity of laser light received by an imaging unit consisting of an imaging element formed of a plurality of pixels, and a peak location calculation block that calculates an approximation function that approximates an intensity distribution of the laser light using the plurality of candidates for peak values detected by the peak value detection block. The peak location calculation block calculates the approximation function that minimizes an error between intensity values of the plurality of candidates for the peak value and values of the approximation function.

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.