US 12,190,924 B1
Laser mode hop compensation using multi-sector feedback in heat assisted magnetic recording
Joey M. Poss, San Jose, CA (US); and Bernhard E. Knigge, San Jose, CA (US)
Assigned to Western Digital Technologies, Inc., San Jose, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on Jan. 15, 2024, as Appl. No. 18/412,710.
Int. Cl. G11B 5/54 (2006.01); G11B 5/596 (2006.01); G11B 5/60 (2006.01); G11B 7/1263 (2012.01); G11B 5/00 (2006.01)
CPC G11B 7/1263 (2013.01) [G11B 5/6029 (2013.01); G11B 5/607 (2013.01); G11B 2005/0021 (2013.01)] 25 Claims
OG exemplary drawing
 
1. A data storage device comprising:
a disk;
a read/write head configured to read data from and write data to the disk;
a laser diode coupled to a nearfield transducer configured to heat an area of the disk near the read/write head;
a first resistive temperature detector (RTD);
a second RTD; and
one or more processing devices configured to:
apply a laser bias to the laser diode during a write operation;
obtain a plurality of differential signal measurements, based at least in part on a plurality of measurements from each of the first RTD and the second RTD; and
adjust the laser bias applied to the laser diode, based at least in part on comparing the plurality of differential signal measurements to a target value for the differential signal.