Laser adjustment during field operation of a heat-assisted magnetic recording data storage device

A method, comprising:

• during field operation of a heat-assisted magnetic recording data storage device, repeatedly performing a laser adjustment procedure, the laser adjustment procedure comprising:
• using a current setting of laser current, writing, at a designated location on a recording medium, a first isolated single test track and at least test three tracks at an unsqueezed pitch, a second test track being in the middle of the at least three tracks;
• comparing a first bit error rate of the first test track with a second bit error rate of the second test track;
• and
• in response to the comparison satisfying a threshold, sweeping the laser current while recording squeezed test tracks at the designated location to determine a new laser current that results in a minimum bit error rate, and using the new laser current for subsequent write operations.

An apparatus, comprising:

• a preamplifier section configured to communicate with a read/write head of a heat-assisted magnetic recording data storage device;
• and
• and a controller configured to, during field operation of the apparatus, repeatedly perform a laser adjustment procedure via the preamplifier section, the laser adjustment procedure comprising:
• using a current setting of laser current, writing, at a designated location on a recording medium, a first isolated single test track and at least three tracks at an unsqueezed pitch, a second track being in the middle of the at least three tracks;
• making a first comparison between a first bit error rate of the first track with a second bit error rate of the second track;
• making a second comparison between the second bit error rate and a reference bit error rate;
• and
• in response to the comparison satisfying a threshold, sweeping the laser current while recording squeezed test tracks at the designated location to determine anew laser current that results in a minimum bit error rate and using the new laser current for subsequent write operations.