US 12,347,472 B1
Positive laser bias electrical control architecture for dark laser heating in heat assisted magnetic recording
John T. Contreras, Palo Alto, CA (US); and Joey M. Poss, Rochester, MN (US)
Assigned to Western Digital Technologies, Inc., San Jose, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on Jan. 3, 2024, as Appl. No. 18/402,926.
Int. Cl. G11B 5/02 (2006.01); G11B 5/012 (2006.01); G11B 7/1267 (2012.01); G11B 13/08 (2006.01); G11B 5/00 (2006.01)
CPC G11B 7/1267 (2013.01) [G11B 5/012 (2013.01); G11B 13/08 (2013.01); G11B 2005/0021 (2013.01)] 22 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 near field transducer (NFT) configured to heat an area of the disk near the read/write head;
an asymmetric laser diode driver configured to drive the laser diode; and
one or more processing devices or components configured, individually or in combination, to:
preheat the laser diode to a target temperature, wherein the preheating comprises:
generating, based at least in part on the target temperature, at least one bias pulse conforming to a plurality of tunable parameters, the plurality of tunable parameters including one or more amplitude parameters, wherein the one or more amplitude parameters comprise one or more of: (1) a first laser diode bias current (IP) greater than a lasing threshold current, (2) a second laser diode bias current (IN) lower than the lasing threshold current, (3) a first duration (TPD), and (4) a second duration (TND); and
applying, using the asymmetric laser diode driver, the at least one bias pulse to the laser diode such that no optical response is produced by the laser diode; and
initiate a write operation for writing data to the disk.