Seagate Technology Incorporated

John Bernard McGurk

Aidan Dominic Goggin

Reyad Mehfuz

Christopher Neil Harvey

Kelly Elizabeth Hamilton

Kelly Elizabeth Callan

Mark Anthony Gubbins

Choon How Gan

Christopher Gerwyn Ward

An apparatus includes a substrate. A laser is formed on a non-self supporting structure and bonded to the substrate. A waveguide having a gap portion is deposited proximate the laser. The waveguide is configured to communicate light from the laser to a near-field transducer (NFT) that directs energy resulting from plasmonic excitation to a recording medium. An optical isolator is disposed over the gap portion.

Waveguide with optical isolator for heat-assisted magnetic recording

An apparatus includes an input coupler configured to receive light excited by a light source. A near-field transducer (NFT) is positioned at a media-facing surface of a write head. A layered waveguide is positioned between the input coupler and the NFT and configured to receive the light output from the input coupler in a transverse electric (TE) mode and deliver the light to the NFT in a transverse magnetic (TM) mode. The layered waveguide comprises a first layer extending along a light-propagation direction. The first layer is configured to receive light from the input coupler. The first layer tapers from a first cross track width to a second cross track width where the second cross track width is narrower than the first cross track width. The layered waveguide includes a second layer that is disposed on the first layer. The second layer has a cross sectional area in a plane perpendicular to the light propagation direction that increases along the light propagation direction. The cross sectional area of the second layer is smaller proximate to the input coupler and larger proximate to the NFT. The layered waveguide includes an interface between the first layer and the second layer, the interface comprises a curve.

Curved-edge optical mode converter for heat-assisted magnetic recording

A recording head has a waveguide core with an input end proximate an energy source at an input surface of the recording head. The waveguide core couples light from the energy source to a near-field transducer that heats a recording medium in response to the light. An input coupler extends along the waveguide core from the input end to a termination region that is away from the input end in a light propagation direction. The input coupler has a first refractive index between that of the waveguide core and a surrounding material. The input coupler is wider than the waveguide core and has a slanted edge at the termination region. The slanted edge crosses the waveguide core such that the input coupler narrows to a neck away from the waveguide core in a crosstrack direction.

Input coupler with features to divert stray light from a waveguide

An input waveguide is disposed on a substrate-parallel plane and configured to receive light from an input surface. A mode converter joins the input waveguide at a junction away from the input surface. The mode converter converts the light from a fundamental mode to a higher-order mode. An input coupler is proximate to and overlapping the input waveguide parallel to the substrate-parallel plane. The input coupler extending from the input surface to the mode converter and has an asymmetric taper that transitions from a wider crosstrack dimension near the input surface to a narrower crosstrack dimension away from the input surface.

Waveguide input coupler with asymmetric taper

A recording head has a waveguide core with an input facet at an input surface. The waveguide core extends to a near-field transducer at a media-facing surface of the recording head. First and second cladding regions are co-planar with and on either cross-track side of the waveguide core. First and second pseudo-slab regions are co-planar with and on outer cross-track sides of the respective first and second cladding regions. The first and second pseudo-slab regions have an index of refraction higher than that of the first and second cladding regions. The first and second pseudo-slab regions confine and channel stray light away from the near-field transducer.

Heat-assisted magnetic recording head having waveguide with outer pseudo-slab that confines stray light

A write head comprises a waveguide core configured to receive light emitted in a crosstrack direction from a light source at a fundamental transverse electric (TE) mode. The waveguide core comprises a first turn that receives the light in the crosstrack direction redirects the light to an opposite crosstrack direction and a second turn that redirects the light to a direction normal to a media-facing surface of the write head. The waveguide core comprises a straight section that couples the first and second turns and a branched portion extending from the straight section. The branched portion is configured to convert the light to a higher-order (TE) mode. A near-field transducer at the media-facing surface is configured to receive the light at the TEmode from the waveguide and directs surface plasmons to a recording medium in response thereto.

Waveguide having mode converter for heat-assisted magnetic recording device

A recording head has a primary waveguide core with an input end at an input surface of the recording head and extends to a near-field transducer at a media-facing surface of the recording head. A secondary waveguide core is separated from the primary waveguide core by a gap such that light is evanescently coupled from the primary waveguide core to the secondary waveguide core. The secondary waveguide core has first and second bends such that an output end of the secondary waveguide core is parallel to and separated from the primary waveguide core in a cross-track direction. A polarization rotator rotates a polarization of light in the secondary waveguide core such that polarization-rotated light exits the secondary waveguide core at the media-facing surface.

Secondary alignment waveguide with polarization rotator

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.

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Derry, United Kingdom

John Bernard McGurk