Abstract: First and second different write precompensation values are associated with different first and second non-return-to-zero, inverted (NRZI) data patterns. The first and second different write precompensation values cause a predetermined phase shift to be written into test data that comprises the first and second NRZI data patterns. The test data is mitten to a recording medium of a storage device using the first and second write precompensation value. The test data is used to determine a response of the storage device to the predetermined phase shift.

Abstract: During field operation of a heat-assisted magnetic recording data storage device, a laser adjustment procedure is performed. The laser adjustment procedure involves writing on a recording medium at least three tracks. If a bit error rate of a middle tracks has increased, the laser current is swept while recording test tracks to determine a new laser current that results in a minimum bit error rate. The new laser current is used for subsequent write operations.

Abstract: During field operation of a heat-assisted magnetic recording data storage device, a laser adjustment procedure is performed. The laser adjustment procedure involves writing on a recording medium at least three tracks. If a bit error rate of a middle tracks has increased, the laser current is swept while recording test tracks to determine a new laser current that results in a minimum bit error rate. The new laser current is used for subsequent write operations.

Abstract: A change in an optical energy profile of energy emitted from a read/write head is determined. The read/write head includes an optical transmission path that emits the energy to heat a heat-assisted recording medium during writing. A change in optical efficiency of the read/write head is also determined. Based on the change in the optical energy profile and the change in the optical efficiency, a change in the effectiveness of the read/write head is determined, and in response a mitigation is performed.

Abstract: A signal is recorded over at least part of a track a heat-assisted recording medium via a heat-assisted magnetic recording head. Symmetry of a cross-track profile of the recorded signal is determined, and the recording head is qualified based on the symmetry of the cross-track profile.

Abstract: During field operation of a heat-assisted magnetic recording data storage device, a laser adjustment procedure is repeatedly performed. The laser adjustment procedure involves writing, at a designated location on a recording medium at least three tracks at an unsqueezed pitch, a first track being in the middle of the at least three tracks. A first bit error rate of the first track is compared with a reference bit error rate. In response to the comparison satisfying a threshold, the laser current is swept while recording squeezed test tracks at the designated location to determine a new laser current that results in a minimum bit error rate. The new laser current is used for subsequent write operations.

Abstract: A power level is applied to a laser that heats a heat-assisted recording medium is increased during recording for a plurality of iterations. Each iteration involves writing test data to a plurality of sequential tracks of the recording medium using the power level and determining bit error rates of the test data. Based on the bit error rates of the iterations, a power boost profile is determined. The power boost profile starts at a baseline level at a first track of a plurality of sequentially-written tracks, incrementally increases to a steady-state level over a first portion of the tracks, and remains at the steady-state level over subsequent ones of the tracks. The power boost profile is applied to the laser when recording to the recording medium.