An apparatus includes a storage medium operable to store a number of data tracks, a read channel circuit operable to process the data tracks read from the storage medium, and a track quality classifier circuit operable to determine a track quality metric for the data tracks read from the storage medium. The track quality metric indicates whether a corresponding one of the data tracks that has failed to successfully process in the read channel circuit can be reprocessed within a track gap period.

An apparatus includes a storage medium operable to store a number of data tracks, a read channel circuit operable to process the data tracks read from the storage medium, and a track quality classifier circuit operable to determine a track quality metric for the data tracks read from the storage medium. The track quality metric indicates whether a corresponding one of the data tracks that has failed to successfully process in the read channel circuit can be reprocessed within a track gap period.

The recording and reproducing apparatus according to the present disclosure includes: a light source; an optical system configured to divide a beam from the light source, and to form a first optical spot and a second optical spot on a recording medium; a recording circuit configured to drive the light source and to modulate a light amount of the light source, and further to record the information on the recording medium by the first optical spot by modulating the light amount of the light source based on information; and an evaluation circuit configured to evaluate the information recorded on the recording medium by reproducing by the second optical spot in a period in which the recording circuit causes the light source to emit the beam at a constant light amount.

An apparatus and method provide for performing, using a heat-assisted magnetic recording head, multiple sequential writes to a recording medium, and recording a metric of write performance for each of the writes. The apparatus and method further provide for calculating fluctuations in the metric, detecting whether the head has a laser mode hopping problem using the metric fluctuations, and categorizing a severity of the laser mode hopping problem.

A laser power applied to a recording head is changed for a plurality of iterations. Each iteration involves, via the recording head at each laser power, writing multiple adjacent tracks to a heat-assisted recording medium and determining a bit error rate for at least one of the adjacent tracks at each laser power. A first laser power is found that achieves a minimum bit error rate of the iterations. An operational value of laser power that is smaller than the first laser power is used during operational recording to reduce adjacent track interference.