Waveguide with reflective grating for localized energy intensity
View Patent ↗An apparatus includes a waveguide with first and second sections, and a junction coupling the first and second waveguide sections together. The first waveguide section has a first reflective device and the second section comprising a second reflective device arranged to generate a standing wave in the waveguide with maximum energy wave intensity at a target region of the waveguide in response to an incident energy wave being provided into at least one of the waveguide sections.
1. A heat assisted magnetic recording (HAMR) apparatus, comprising:
a waveguide comprising a cladding and a core, the core having a plurality of protrusions extending into the cladding;
a near field transducer;
an energy source arranged to propagate light through the waveguide to the near field transducer, and
wherein the waveguide comprises first and second sections coupled together at a junction and wherein the waveguide is configured to optimize a normalized peak intensity of the light at a target region of the waveguide.
2. The apparatus of claim 1 , wherein the plurality of protrusions are square-shaped.
3. The apparatus of claim 1 , wherein the plurality of protrusions are curve-shaped.
4. The apparatus of claim 1 , wherein the plurality of protrusions are partially reflective.
5. The apparatus of claim 1 , wherein at least one of the first and second sections comprises the plurality of protrusions, wherein the waveguide is configured to have a number of protrusions that optimizes a normalized peak intensity of the light at a target region of the waveguide.
6. The apparatus of claim 5 , wherein each of the first and second sections of the waveguide have a respective portion of the plurality of protrusions, wherein each of the first and second sections of the waveguide receive an incident light wave from the energy source and a reflected light wave reflected by the plurality of protrusions of the opposite waveguide section to produce a standing wave,
wherein the standing wave includes at least one antinode formed at the target region.
7. The apparatus of claim 6 , wherein the near field transducer is arranged adjacent to the target region of the waveguide.
8. A magnetic hard disk drive, comprising:
a rotatable magnetic recording disk;
a slider comprising a heat assisted magnetic recording (HAMR) device having a
near field transducer (NFT);
a waveguide comprising a cladding and a core, the core having a plurality of protrusions extending into the cladding; and
an energy source arranged to propagate light through the waveguide to the near field transducer;
wherein the NFT is arranged adjacent to the waveguide, the NFT configured to couple the light to the surface of the recording disk for heat assisted magnetic recording and wherein the waveguide comprises first and second sections coupled together at a junction and wherein the waveguide is configured to optimize a normalized peak intensity of the light at a target region of the waveguide.