Patent ID: 11908499
Assignee: SEAGATE TECHNOLOGY LLC
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 19:
20. A heat-assisted magnetic recording head comprising:
a laser configured to emit electromagnetic radiation;
a near-field transducer configured to focus and emit an optical near-field;
a primary waveguide configured to receive the electromagnetic radiation and propagate the electromagnetic radiation toward and proximal to the near-field transducer;
a secondary waveguide configured to receive a portion of the electromagnetic radiation from the primary waveguide; and
a photodiode configured to receive the portion of the electromagnetic radiation from the secondary waveguide and emit a signal that represents a magnitude of the electromagnetic radiation that the laser emits, the secondary waveguide further configured to mitigate reflections of the electromagnetic radiation from reaching the photodiode,
wherein:
the primary waveguide comprises an end adjacent to the laser,
a segment of the primary waveguide that comprises the end of the primary waveguide is coupled to a coupler configured to direct electromagnetic radiation emitted by the laser into the primary waveguide, the coupler comprising an escape slab configured to disperse stray electromagnetic radiation, and
the secondary waveguide comprises a first end and a second end, the first end being adjacent to the photodiode and a segment of the secondary waveguide that comprises the second end is coupled to the escape slab.