Angled Plasmonic Waveguide for HAMR Energy Delivery
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Solution Overview
Problem
Current heat-assisted magnetic recording (HAMR) technologies face limitations in areal data density due to superparamagnetic effects, which are overcome by locally heating a small portion of the magnetic medium to its Curie temperature, but this requires efficient energy delivery to a small area, which is challenging with conventional optical delivery paths.
Innovation Solution
A plasmonic waveguide is integrated within the recording head, using a high-refractive-index material and a plasmonic metal such as gold or silver to guide light from a laser diode to a recording medium, exciting surface plasmons and delivering energy efficiently through a near-field transducer, allowing for localized heating beyond the Curie temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional optical delivery paths are used to heat the recording medium, then the structure is simple, but the energy delivery efficiency to a small area is insufficient
Solution Approach 1:
The patent introduces a plasmonic waveguide as an intermediary component between the laser source and the recording medium. This waveguide uses surface plasmons to transfer optical energy with high efficiency to a focused spot on the medium, overcoming the limitations of conventional optical delivery paths while maintaining a relatively compact structure.
Solution Approach 2:
The patent replaces conventional mechanical/optical delivery systems with a plasmonic-based energy transfer mechanism. By using surface plasmons in a waveguide structure, the system achieves more efficient energy concentration and delivery to the recording medium compared to traditional optical paths.
2Reliability
If a small portion of the magnetic medium is heated to its Curie temperature, then superparameteric effects are overcome and areal data density is enhanced, but efficient energy delivery to such a small area becomes challenging
Solution Approach 1:
The patent employs a plasmonic waveguide that concentrates optical energy into a highly localized spot on the recording medium. This local concentration of energy enables heating of a very small area to the Curie temperature, which is essential for overcoming superparameteric effects and achieving high areal data density while maintaining reliable data storage.
3Productivity
If surface plasmons are excited and guided through a plasmonic waveguide, then energy delivery to a small region is efficient, but the device structure becomes more complex
Solution Approach 1:
The plasmonic waveguide is divided into multiple segments with different geometries and orientations. This segmentation allows for flexible routing and focusing of surface plasmons to achieve rapid heating of the recording medium while managing the overall structural complexity through modular design.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The plasmonic waveguide enables efficient energy delivery to a small region of the recording medium, overcoming superparamagnetic effects and enhancing areal data density by achieving localized high temperature rises, thereby reliably storing data.
Implementation Method 1
In response to receiving the light, surface plasmons are excited and guided to an end of the first elongated portion
Implementation Method 2
The angle of the first elongated portion is selected so that total internal reflection of the light is achieved
Implementation Method 3
The surface plasmons are delivered to heat a portion of a recording medium via the output surface
Data Source
AI summary
An apparatus includes an input region having a high-refractive-index material and an input surface configured to receive light emitted from a laser. An output surface of the apparatus is configured to deliver energy to a recording medium. The apparatus includes a plasmonic waveguide having a first elongated portion at an angle to the input surface and configured to receive the light through the input region. In response to receiving the light, surface plasmons are excited and guided to an end of the first elongated portion. The plasmonic waveguide includes a second elongated portion coupled to the end of the first elongated portion and configured to guide the surface plasmons to the output surface.