Near field transducer driven by a transverse electric waveguide for energy assisted magnetic recording
View Patent ↗An apparatus includes dielectric waveguide cores operating in transverse electric (TE) mode configured to receive incident light energy from an energy source and direct the incident light energy to a target. A near field transducer (NFT) is configured to focus the light energy received from the waveguide cores and to transmit the focused light energy onto a storage disk surface to generate a heating spot. The NFT includes propagating surface plasmon polariton (PSPP) elements that are energized by the light energy from the waveguide cores. Each PSPP element has a plasmonic metal bar disposed above a surface of a single waveguide core in a longitudinal alignment with the waveguide core, a first end that receives the light energy from the waveguide core, and a second end exposed to the air bearing surface. The width of each metal bar tapers toward the first end.
1. An apparatus for energy assisted magnetic recording of a storage disk, comprising:
a plurality of dielectric waveguide cores operating in transverse electric (TE) mode configured to receive incident light energy from an energy source and direct the incident light energy to a target; and
a near field transducer formed at the air bearing surface and configured to focus the light energy received from the plurality of waveguide cores and to transmit the focused light energy onto the storage disk surface to generate a heating spot on the storage disk, the near field transducer comprising:
a plurality of propagating surface plasmon polariton (PSPP) elements that are energized by the light energy from the waveguide cores, wherein each of the PSPP elements comprises a plasmonic metal bar disposed above a surface of a single waveguide core in a longitudinal alignment with the waveguide core, each metal bar having a first end that receives the light energy from the waveguide core, and a second end exposed to the air bearing surface, wherein the width of each metal bar tapers toward the first end.
2. The apparatus of claim 1 , wherein one side along the width of the PSPP element is entirely linear and longitudinally aligned with the waveguide core, and at least a portion of the opposite side of the PSPP element is sloped to form the tapering toward the first end.
3. The apparatus of claim 1 , wherein at least a portion of both sides of the PSPP element is sloped to form the tapering toward the first end.
4. The apparatus of claim 1 , wherein a gap exists between each of the plurality of plasmonic metal bars and the corresponding surface of the respective waveguide core.
5. The apparatus of claim 1 , wherein
each of the waveguide cores and corresponding PSPP elements is substantially linear and comprises a first end and a second end,
the second ends of all PSPP elements are connected together at a junction point near the air bearing surface with at least a portion of the junction exposed on the air bearing surface.
6. The apparatus of claim 3 , wherein the plurality of waveguide cores and corresponding PSPP elements are configured in a three dimensional arrangement with respect to the air bearing surface.
7. The apparatus of claim 1 , wherein the plurality of PSPP elements provides constructive interference of the incident light energy at the target.
8. The apparatus of claim 1 , further comprising a plasmonic metal cap disposed above the plasmonic metal bars and coupled to the plasmonic metal bars.
9. The apparatus of claim 6 , further comprising a magnetic pole disposed above the plasmonic cap.
10. An apparatus for energy assisted magnetic recording of a storage disk, comprising:
a plurality of dielectric waveguide cores operating in transverse electric (TE) mode configured to receive incident light energy from an energy source and direct the incident light energy to a target; and
a near field transducer formed at the air bearing surface and configured to focus the light energy received from the plurality of waveguide cores and to transmit the focused light energy onto the storage disk surface to generate a heating spot on the storage disk, the near field transducer comprising:
a plurality of propagating surface plasmon polariton (PSPP) elements that are energized by the light energy from the waveguide cores, wherein each of the PSPP elements comprises a plasmonic metal bar disposed above a surface of a single waveguide core in a longitudinal alignment with the waveguide core, each metal bar having a first end that receives the light energy from the waveguide core, and a second end exposed to the air bearing surface, each metal bar arranged with a portion that extends beyond the perimeter of the surface of the waveguide facing the metal bar.
11. An apparatus for energy assisted magnetic recording of a storage disk, comprising:
a plurality of dielectric waveguide cores operating in transverse electric (TE) mode configured to receive incident light energy from an energy source and direct the incident light energy to a target; and
a near field transducer formed at the air bearing surface and configured to focus the light energy received from the plurality of waveguide cores and to transmit the focused light energy onto the storage disk surface to generate a heating spot on the storage disk, the near field transducer comprising:
a plurality of propagating surface plasmon polariton (PSPP) elements that are energized by the light energy from the waveguide cores, wherein each of the PSPP elements comprises a plasmonic metal bar disposed above a surface of a single waveguide core in a longitudinal misalignment with the waveguide core, each metal bar having a first end that receives the light energy from the waveguide core, and a second end exposed to the air bearing surface, each metal bar arranged with a portion that extends beyond the perimeter of the surface of the waveguide facing the metal bar.
12. A magnetic storage disk drive, comprising:
a rotatable storage disk;
a laser diode;
a plurality of dielectric waveguide cores operating in transverse electric (TE) mode coupled together at a junction near an air bearing surface of a magnetic recording device, each waveguide core configured to receive incident light energy from the laser diode; and
a near field transducer formed at the air bearing surface for focusing light energy received from the waveguide core and transmitting the focused light energy onto the storage disk surface to generate a heating spot, comprising:
a plurality of propagating surface plasmon polariton (PSPP) elements that are energized by the light energy from the waveguide cores, wherein each of the PSPP elements comprises a plasmonic metal bar disposed along a longitudinal centerline of a surface of a single waveguide core, each metal bar having a first end with a tapered width for receiving the light energy from the waveguide core, and a second end with a fixed width at the air bearing surface being approximately equal to the width of the waveguide core.