A gradient-index lens couples light from a laser active region to a waveguide core. The gradient-index lens includes a plurality of bilayers, each of the bilayers having first and second material of respective first and second refractive indices. The bilayers conform to a planar base of the gradient-index lens and further conform to input and output sidewalls of the gradient-index lens. The input sidewall faces the laser active region and the output sidewall faces away from the laser active region. The input and output sidewalls are tilted at respective acute angles relative to the planar base.

A slider configured for heat-assisted magnetic recording has an upper surface, an opposing air bearing surface (ABS), and a body defined between the upper surface and the ABS. The slider comprises a write pole and a near-field transducer (NFT) at or near the ABS. An optical waveguide is configured to receive light from a laser source and comprises a first cladding layer, a second cladding layer, and a core between the first and second cladding layers. The core has a width, a length, and a longitudinal axis oriented along the length of the core. A bolometer is situated within the body of the slider at a location that receives at least some of the light communicated along the waveguide used during a writing operation. The bolometer is spaced apart from the core and comprises a longitudinal axis that is oriented substantially parallel to the longitudinal axis of the core.

Devices that have an air bearing surface (ABS), the device includes a near field transducer (NFT) that includes a disc configured to convert photons incident thereon into plasmons; and a peg configured to couple plasmons coupled from the disc into an adjacent magnetic storage medium, wherein the disc includes a disc material that includes gold or an alloy thereof and the peg includes a peg material, wherein the disc material is different from the peg material and wherein the peg material has a real part of the permittivity that is not greater than that of gold.

A storage device performs a background operation involving seeking a read/write head between inner and outer diameters of a disk of the storage device. During the seeking, adjacent test tracks are written at a diameter between the inner and outer diameters of the disk. The adjacent test tracks are written using varying levels of laser power applied to the disk via the read/write head. An optimum value of the laser power is determined based on reading at least one of the adjacent test tracks.

An apparatus, according to one embodiment, comprises a near field transducer; an adhesion layer on a media facing side of the near field transducer, the adhesion layer comprising Ni and Cr; and a protective layer on a media facing side of the adhesion layer. Other apparatuses, systems and methods are described in additional embodiments.

A recording head has a near-field transducer proximate a media facing surface of the read/write head. A waveguide overlaps and delivers light to the near-field transducer. A subwavelength focusing mirror is at an end of the waveguide proximate the media-facing surface. The subwavelength focusing mirror recycles a residual transverse field for excitation of the near-field transducer.

The system and corresponding process includes a system for producing a mechanical image of original audio source media and a system for encoding the mechanical image information into a digital file. A processing system recovers the mechanical image information from the digital file at a receiving end. Audio processing is used to produce the original audio source material without the standard losses associated with digital encoding of audio material.

A storage device includes a storage controller configured to operate a heat-assisted magnetic recording head to write data to a band of consecutive data tracks in a consecutive track order while selectively alternating a power level of the heat source when writing to some data tracks of the band.

An apparatus and method provide for performing, using a heat-assisted magnetic recording head, multiple sequential writes to a recording medium, and recording a metric of write performance for each of the writes. The apparatus and method further provide for calculating fluctuations in the metric, detecting whether the head has a laser mode hopping problem using the metric fluctuations, and categorizing a severity of the laser mode hopping problem.

An apparatus includes a waveguide that delivers energy from an energy source, a write pole located proximate the waveguide at a media-facing surface, and a near-field transducer located proximate the write pole in a down track direction. The near-field transducer includes an enlarged portion and a peg extending from the enlarged portion towards the media-facing surface. The peg comprises a taper facing away from the write pole, and the taper causes a reduced down track dimension of the peg near the media-facing surface.