HEAT-ASSISTED MAGNETIC RECORDING (HAMR) DISK DRIVE WITH FLY-HEIGHT SENSING MEANS

摘要

PROBLEM TO BE SOLVED: To provide a heat-assisted magnetic recording (HAMR) disk drive that has fly-height sensing means.SOLUTION: The heat-assisted magnetic recording (HAMR) disk drive with a primary waveguide that directs laser light from a laser diode to a near-field transducer includes a second waveguide for sensing the head-disk spacing or fly-height. The second waveguide has a sensor portion that senses the spacing and directs light representative of the spacing to the second waveguide's output end. The second waveguide may include a second or reference portion that is connected to the sensor portion and directs light representative of light input from the laser diode. The combined light from the two portions is directed to the second waveguide's output end. A detector, which may be a photo-diode, is located at the second waveguide's output end and provides a signal that may be coupled to a thermal fly-height controller to increase or decrease the fly-height.