Light source power control for heat assisted magnetic recording (HAMR)

An apparatus comprising:

• a data recording head adjacent a data storage surface, the head comprising a magnetic transducer and a light source;
• a controller adapted to direct a write operation to write data to a selected sector on the surface by driving the light source to irradiate the surface at a first power level insufficient to alter a magnetization state thereof prior to passage of the selected sector adjacent the magnetic transducer, followed by transitioning the light source to a higher, second power level sufficient to alter the magnetic coercivity of the surface as the selected sector passes adjacent the magnetic transducer to facilitate writing of data thereto by the transducer, and
• a memory which stores a plurality of different power levels in a lookup table for said recording head each operable to alter said magnetic coercivity of the surface sufficient to switch a magnetization state thereof responsive to different system settings wherein the controller selects the second power level from the table responsive to a detected combination of said system settings.

A method comprising:

• driving a light source of a data recording head at a first power level to irradiate an adjacent storage medium prior to writing data to said medium using a magnetic transducer of said head, the first power level insufficient to alter a magnetization state of the medium;
• and
• transitioning the light source to a higher, second power level to irradiate the storage medium during the writing of data to said medium using the magnetic transducer, the second power level sufficient to facilitate an altering of said magnetization state of the medium by the transducer, wherein a magnitude of the second power level is previously selected responsive to application of a higher, third power level to the light source sufficient to establish contact between the data recording head and the medium.